👉 TAP TO SAVE 30% WITH CODE NEW
X
Lost password?

Don't have an account?
Gain Access Now

X

Receive free daily analysis

NFL
NBA
NHL
NASCAR
CFB
MLB
MMA
PGA
ESPORTS
BETTING

Already have an account? Log In

X

Forgot Password


POPULAR FANTASY TOOLS

Expert Advice
Articles & Tools
Import Your Leagues
Draft Rankings
Draft Simulator
Enter League Settings
Compare Any Players
Rookies & Call-Ups
24x7 News and Alerts

Fantasy Baseball Dynasty Prospects: Top 10 First Basemen

Marc Hulet provides dynasty league fantasy baseball owners with his top 10 first base prospects heading into the 2020 MLB season.

The offseason positional prospect rankings were launched last week at Rotoballer with a detailed look at the Top 10 catchers. Today, it’s the first base prospects’ turn to be on full display.

There also aren’t a ton of “can’t miss” first base prospects in the pro ranks right now with only one sitting on my “must-have” list right now. But there are still a number of players that could be excellent sources of power for a relatively low acquisition cost -- although there is definitely no future Peter Alfonso to be found here. With that said, the Twins have a sleeper first base prospect that could end up having a breakout season similar to the one Christian Walker had in 2019 for Arizona.

The first basemen rankings are based on the assumption that the Triple-A and MLB baseballs will continue to be juiced in 2020, although many of the players listed have such strong raw power that they’ll produce outstanding power numbers either way.

Be sure to check all of our fantasy baseball draft tools and resources:

Top 10 First Base Prospects

1. Andrew Vaughn, White Sox, 2020 Level: A+

Prior to the 2019 amateur draft, I advocated for Vaughn to go first overall to the Orioles. Instead, Baltimore went with the industry consensus and took college catcher Adley Rutschman while the U of California first baseman was popped third overall by Chicago. Vaughn had a nice pro debut in 2019 despite being pushed overly aggressively by his new club. He played at three levels and topped out in High-A ball. There were some positive indicators with Vaughn’s performance even if he was more good than great. He posted a BB-K of 30-38 in 55 games, which should bode well for his future ability to hit for a strong average. As well, 23 of his 57 hits went for extra bases — including 17 doubles. High doubles totals are usually a strong indicator of future home-run power once players start to lift the ball in the air more consistently and add muscle/strength. There is the potential here for Vaughn to be a .280-.300 hitter with 30 or more home runs.

2. Triston Casas, Red Sox, 2020 Level: A+

The Red Sox have a very thin farm system in terms of potential impact players but Casas is one player that possesses a lot of potential for the future. He could have some additional value for fantasy players if he can earn dual eligibility at both first base and third base once he reaches the Majors. Just 19 years old, this 2018 first-rounder had a solid first full season in the Majors. He averaged just shy of one strikeout per game but displayed plus power by going deep 19 times — good for third in the league behind two players spending their second straight seasons in the league. He also took 58 walks in 120 games, which is encouraging for such a young player. It will be at least two years before Boston fans see Casas in the Majors but he should be well worth the wait.

3. Brent Rooker, Twins, 2020 Level: AAA

It might seem like a bit of a stretch to have Rooker listed this high — and on the first base list at all. He didn’t play a single inning at first base in 2019. Instead, he spent most of his time in left field for the Twins’ Double-A club. However, Rooker spent a good chunk of his junior year of college at first base and also racked up 55 games there in the minors over the first two years of his pro career. As a modest fielding outfielder, it wouldn’t be a shock to see him develop into a dual-position-eligible-player in fantasy baseball once he reaches the Majors. Rooker has massive power potential and has consistently produced outstanding line-drive and isolated slugging rates throughout his three years in pro ball. He likely won’t hit for a ton of average because his strikeout rates are also consistently high (35% at Triple-A in 2019) but he takes a lot of walks, which will be of benefit in leagues that reward walks. Rooker is on my list of sleeper prospects to watch for 2020 — especially if the same baseball is used next year.

4. Evan White, Mariners, 2020 Level: AAA

White is a player that could really benefit from the balls that were used at Triple-A and in the Majors in 2019. A strong offensive performer in college, his success with hitting for average has carried over into pro ball but his power has not developed at expected. White has a strong frame and the potential to hit for pop but his approach and swing have long been geared towards using the whole field and hitting line drives more to than aiming for over-the-fence results. That started to change at Double-A in 2019 when he began to put the ball in the air much more consistently — and he reached a career-high in home runs at 18 despite playing in just 92 games. One thing to keep an eye on, though, is that he also posted a career-low walk rate so we’ll hope for a bounce-back in this area in 2020.   

5. Ryan Mountcastle, Orioles, 2020 Level: AAA

Mountcastle moved from third base to first base in 2019. He then also saw time in left field late in the season as Baltimore experimented with different ways to get his bat into the big league lineup. The defensive versatility could be a boon to his fantasy value if he becomes eligible at all three positions. The offensive game, though, is Mountcastle’s claim to fame thanks to his impressive raw power. He slugged 25 home runs in just 127 games at Triple-A in 2019 while also adding another 35 doubles. A .300 batting average is likely not in the cards for Mountcastle, despite his 2019 output, as he relied heavily on his Batting Average on Balls in Play (BABIP) which was an unsustainable .370. His BB-K of 24-130 also leaves a lot to be desired.

6. Bobby Bradley, Indians, 2020 Level: AAA

Bradley is similar to Mountcastle but with a little less feel for the hit tool but better patience. If your fantasy league counts walks then you probably want to flip the two players in the rankings. Bradley’s power output has been extremely consistent throughout his pro career and he’s hit fewer than 27 home runs in a season only once over the past six seasons. If he can make enough contact against big league pitchers, Bradley has 30 home run potential but it would likely come with 180-200 strikeouts. The young first baseman doesn’t have a clear path to playing time in the Majors for 2020 with Franmil Reyes and Carlos Santana (who has a contract option) possibly acting as roadblocks.

7. Seth Beer, Diamondbacks, 2020 Level: AA

Selected by the Astros in the first round in 2018, Beer reached Double-A in his first full season — and was also a key piece in the 2019 Zack Greinke trade with Arizona. He went deep 26 times while playing for three teams at two different levels but projects as more of a good-not-great future big leaguer. He’s been a solid statistical performer to date but he lacks athleticism and premium bat speed so there is concern about his ability to consistent tap into his raw power against MLB pitching.   

8. Grant Lavigne, Rockies, 2020 Level: A+

The list drops off a bit here. Lavigne is coming off a disappointing season. Drafted 42nd overall in 2018, the hulking teenaged first baseman struggled to tap into his raw power potential and just 26 of his 104 hits went for extra-base hits. He hit far too many balls on the ground and will likely need to adjust his swing to embrace the fly-ball revolution. Lavigne had a lot of swing-and-miss to his game (129 strikeouts in 126 games) but also showed promising patience (68 walks). If he can consistently tap into his raw power, the young hitter is in the right organization to make a real impact with that tool at the big league level.

9. Lewin Diaz, Marlins, 2020 Level: AA

Diaz started to tap into his considerable potential in 2019. After hitting a career-high 12 home runs in 2018, the young hitter more than doubled his output in 2019 with 27. The Twins prospect attracted the attention of the Marlins and he was acquired in a trade deadline deal. Diaz really struggled after the trade and it’s worth noting that Miami is not as strong at player development as Minnesota. The young left-handed hitter really struggles against same-side pitching so he has a fair bit of work to do to avoid a future platoon role.

10. Michael Toglia, Rockies, 2020 Level: A+

Drafted in the first round out of UCLA in 2019, Toglia may not provide much of a batting average as a pro but he’s shown the ability to produce strong power numbers with wood bats as an amateur — and also during his brief pro debut. He went deep nine times in 41 games in the short-season A-ball league after signing his first pro contract. And while there is some swing-and-miss to his game, he’s also shown a willingness to take a walk and was issued 28 free passes in his debut. Colorado could open 2020 with two top first base prospects in advanced A-ball although Toglia could spend more of his time in the corner outfield, which has the potential to improve his fantasy value.

Just Missed: Bobby Dalbec (Red Sox) and Gavin Sheets (White Sox)

More MLB Prospects Analysis




POPULAR FANTASY TOOLS

Expert Advice
Articles & Tools
Import Your Leagues
Draft Rankings
Draft Simulator
Enter League Settings
Compare Any Players
Rookies & Call-Ups
24x7 News and Alerts
RANKINGS
C
1B
2B
3B
SS
OF
SP
RP

RANKINGS

QB
RB
WR
TE
K
DEF

REAL-TIME FANTASY NEWS

Darius Slay

Retires From the NFL
Jonathan Kuminga

Slated to Suit Up Monday
Seiya Suzuki

Undergoing MRI Exam on Monday
Joe Musgrove

Expected to Open the Year on the Injured List
Peyton Watson

Hopes to Return This Week
Christian Kirk

49ers Sign Christian Kirk to One-Year Deal
Kawhi Leonard

Downgraded to Unavailable on Monday
Matt McCarty

Could Thrive at the Valspar Championship
Michael Kim

Seeks to Dust Off Tough Week at TPC Sawgrass
Max Homa

Enjoying a Solid 2026 Heading into Valspar Championship
Nick Dunlap

Keeps Slugging Through Rough 2026 Season
Zach Neto

Expected to Return to Game Action on Tuesday
Kyren Williams

Will Kyren Williams Remain the Undisputed RB1 in Los Angeles Going Forward?
Mason Taylor

Does Mason Taylor Have Breakout Potential in 2026?
Puka Nacua

Appears Poised to Dominate for Years to Come
Andrew Novak

Wants to Rebound After The Players Championship
Austin Smotherman

on Baby Watch as Valspar Championship Approaches
Ben Sinnott

Does Not Appear to Be in Washington's Long-Term Plans
Luke Clanton

Might Have Issues at the Valspar Championship
Sam Darnold

Profiles as a Safe QB2 in Dynasty Formats Heading into 2026
Jerry Jeudy

Can Jerry Jeudy Bounce Back from Underwhelming 2025 Campaign?
Christiaan Bezuidenhout

Must be Accurate at the Valspar Championship
Josh Emmett

Suffers First-Round TKO Loss
Kevin Vallejos

Scores First-Round TKO
Amanda Lemos

Drops Back-To-Back Fights
Gillian Robertson

Extends Her Win Streak
Zach Neto

to Take Batting Practice on Monday
Andre Fili

Drops Decision on Saturday
Cam Skattebo

Thinks he'll be 100 Percent Healthy in a Little Over a Month
Denny Hamlin

Dominates and Gets His Third Career Las Vegas Win
Chase Elliott

Earns Runner-Up Finish at Las Vegas
William Byron

Wins A Stage and Finishes Third at Las Vegas
Jeremy McNichols

Re-Signs With Commanders
Christopher Bell

Finishes Fourth at Las Vegas After Strong Run
Kyle Larson

Fades to Seventh Despite Leading Laps Early at Las Vegas
Justin Fields

Chiefs Acquiring Justin Fields From Jets
Andre Fili

Jose Delgado Edges Andre Fili in Split-Decision Win
Oumar Sy

Suffers First-Round Submission Loss
Ion Cutelaba

Returns To The Win Column
CFB

CJ Carr Enters Sophomore Season as Heisman Favorite
CFB

Aaron Philo Not a Lock to be Florida's Starting QB?
CFB

George MacIntyre the Favorite to Win Tennessee Quarterback Battle?
CFB

Keelon Russell, Austin Mack Battling for Alabama QB1 Duties
Connor McDavid

Records Three Assists Sunday
Bo Groulx

Makes Big Impact Sunday
Drake Batherson

Pots Two Goals in Sunday's Win
Bobby McMann

Continues Dream Start in Seattle
Kirby Dach

Injured on High Hit
Alexander Wennberg

Without Timeline for Return
Leon Draisaitl

Exits Early with Injury Sunday
Harold Fannin Jr.

Officially Steps Into the Top Role
Max Strus

Makes Impact in Season Debut
Troy Franklin

Ready to Take on an Even Larger Role?
Seth Curry

Sidelined for at Least One Week
Brenton Strange

Trending Up Despite Anticipated Competition?
Al Horford

Set for Re-Evaluation Next Week
A.J. Brown

Eagles to Revisit A.J. Brown Trade Situation in June
Kawhi Leonard

Doubtful Monday Against Spurs
Kayshon Boutte

Steps Into a Larger Role for Now
Santi Aldama

Set for Season-Ending Knee Procedure
Christian McCaffrey

Tough to Justify Trading in Dynasty Leagues
Drew Eubanks

to Undergo Thumb Surgery
Isaiah Collier

Exits Early Sunday with Knee Injury
Troy Terry

Adds Three Points in Return to Lineup
Leo Carlsson

Picks Up Trio of Points on Sunday
Dejounte Murray

Battling Illness Ahead of Monday
Alperen Sengün

Alperen Sengun Could Miss Another Game Monday
Noah Clowney

Sidelined Monday Versus Trail Blazers
Michael Porter Jr.

to Miss Third Straight Game
José Ramírez

Jose Ramirez is Day-to-Day with Shoulder Inflammation
Alexandre Sarr

Out Monday Against Golden State
Jeremy Sochan

Returns to Action Sunday
Ömer Yurtseven

Omer Yurtseven Set to Debut Sunday for Golden State
Quinten Post

Cleared to Play Sunday Against New York
Malik Monk

to Miss Third Straight Game Sunday
Devin Carter

Sidelined Sunday Versus Utah
Brendan Gallagher

Rejoins Canadiens Lineup Sunday
Russell Westbrook

Won't Play Sunday Versus Jazz
Daniil Tarasov

Starting Against Kraken
Quinn Ewers

Set to Back Up New Quarterback
Ty Emberson

Remains Out Sunday
Chris Brooks

the Preferred Handcuff in Green Bay?
Bobby Brink

Questionable Sunday
Kendre Miller

Continues to Fall Out of Favor in New Orleans
Oliver Ekman-Larsson

Unavailable Against Wild
Brashard Smith

Ascension Put on Pause?
Ryan Nugent-Hopkins

a Game-Time Call Sunday
Corbin Carroll

to Resume Playing Defense This Week
John Carlson

Set for Ducks Debut
Francisco Lindor

Non-Committal About Status for Opening Day
Nathan Eovaldi

Named Rangers' Opening Day Starter
Hayden Birdsong

Diagnosed with Grade 2 Forearm Strain and UCL Sprain
Marcelo Mayer

Scratched With Left-Knee Soreness
Zach Neto

Tests Come Back Negative, Dealing With Sprained Hand
Christopher Bell

Looking for Redemption, Wins Pole at Las Vegas
Denny Hamlin

Should Contend for Another Vegas Win
Chase Briscoe

Qualifies 18th Despite Toyota Dominating at Las Vegas
Chase Elliott

May Fly Under the Radar at Las Vegas
NASCAR

Ross Chastian Has Been As Solid As They Come at Las Vegas
Ty Gibbs

Could Ty Gibbs Finally Break Through With a Win at Las Vegas?
Brad Keselowski

a Solid DFS Pick at Las Vegas
Francisco Lindor

is Making Spring Debut on Sunday
Carter Verhaeghe

Anton Lundell Expected to Return Sunday
Kyle Larson

Should Kyle Larson be Considered A Favorite for Las Vegas?
Sam Bennett

Considered Day-to-Day
William Byron

Could Compete for a Top-Five Finish at Las Vegas
Sam Reinhart

Not Traveling on Four-Game Road Trip
Ryan Blaney

Is Ryan Blaney Worth Rostering in Tournament DFS Lineups for Las Vegas?
Michael Rasmussen

Ruled Out for One Week
Tyler Reddick

Could Continue his Top-10 Streak at Las Vegas
Declan Carlile

to Miss 4-5 Weeks
Joey Logano

Should DFS Managers Underestimate Joey Logano for Las Vegas?
Chris Buescher

Is Chris Buescher Worth Rostering For Las Vegas DFS Lineups?
NASCAR

Bubba Wallace is A Risky DFS Option Who Could Pay Off at Las Vegas
Josh Berry

Has Plenty of Upside for Las Vegas DFS Lineups
Ryan Preece

Scores his First Las Vegas Top-10 Starting Spot in Qualifying
Seiya Suzuki

Leaves WBC Game on Saturday With Right-Knee Discomfort
Zach Neto

is Removed After Suffering Hand Injury
Joe Ryan

Won't Pitch in the World Baseball Classic
Zack Wheeler

Throws First Live BP Session on Saturday
Merrill Kelly

Expected to Open Season on the Injured List
Kevin Gausman

Named Toronto's Opening Day Starter
Kyle Stowers

Back in Grapefruit League Lineup
Francisco Lindor

Takes Full Batting Practice on Friday
Brandon Woodruff

Still TBD for Opening Day
Kevin Vallejos

Looks To Remain Undefeated In The UFC
Josh Emmett

In Dire Need Of Victory
Gillian Robertson

A Favorite At UFC Vegas 114
Amanda Lemos

Set For Co-Main Event
Oumar Sy

Looks To Win Back-To-Back Fights
Ion Cutelaba

Looks To Get Back In The Win Column
Hideki Matsuyama

Brings Strong Course History to TPC Sawgrass
Adam Scott

in Strong Form Ahead of The Players
Rickie Fowler

on Quite the Run Heading to TPC Sawgrass
Sepp Straka

Needs to Forget What Happened Sunday at Bay Hill
Jordan Spieth

an Enigma Heading to The Players Championship
Justin Rose

Trying to Pick Up the Pieces in Florida
Maverick McNealy

Bounces Back at Arnold Palmer Invitational
Brooks Koepka

Continues His Florida Swing With Some Momentum
Nicolai Hojgaard

in Strong Form Ahead of The Players
Robert MacIntyre

a Volatile Option at The Players
Matt Fitzpatrick

Looks to Return to Top Form at The Players
Sam Burns

a High-Risk, High-Reward Option at The Players
Keegan Bradley

Hard to Trust at The Players