Later-Round Breakout Candidates and Fantasy Baseball Sleepers - NL Edition

The term "sleeper" is a big buzzword in the fantasy sports world because, in addition to nailing your first few picks, one must take risks on late-round players who have shown signs of upside or "flashes" of success but perhaps haven't been consistent throughout a full season to garner a top-20 pick.

In this piece, I will focus on National League sleepers and late-round fliers to help you bolster your roster for the upcoming fantasy baseball season. I'll discuss one hitter and a few pitchers, each with an average ADP of 240.0 or higher, according to  NFBC.

RotoBaller uses NFBC because it's the most active platform for fantasy baseball. This ADP gives us a more informed look at the market because there have been hundreds of drafts in these high-stakes leagues. We also have RotoBaller MLB Rankings available for you to cross-reference to help make informed decisions. Be sure to keep following @RotoBallerMLB and me @NichoRoessler on X for more league-winning offseason content. Best of luck in your upcoming drafts, RotoBallers. Enjoy the rush we all get from drafts!

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DJ Herz, SP, Washington Nationals

Washington Nationals left-handed pitcher DJ Herz, who is 24 years old, is looking to build on an impressive rookie season in 2024 in which he went 4-9 with a 4.16 ERA, 3.71 FIP, and 1.26 WHIP with a 28.7 percent strikeout rate and a 9.4 percent walk rate in 88 2/3 innings pitched over his first 19 MLB starts.

Herz, a former eighth-round pick by the Chicago Cubs in 2019, spent his first four seasons with the Cubs' minor league system before being traded to the Nationals in a deal that sent Jeimer Candelario to the Cubs. 

Based on the underlying numbers, Herz got a bit unlucky in 2024, as his 4.16 ERA was nearly half a point higher than his 3.71 FIP and nearly a full run higher than his 3.26 xERA. What intrigues me about Herz is that he ranked in the 78th percentile in whiff percentage and 81st percentile in strikeout percentage. Point blank, he strikes people out.

What's even more impressive is that he mostly relies on three pitches: a four-seamer (54.2 percent), changeup (24.5 percent), and slider (17.9 percent), having only thrown his knuckle curve 3.3 percent of the time. Herz relies heavily on his fastball, allowing a .222 BA, .194 xBA, and .317 slugging percentage while generating a 30.5 percent whiff rate with his fastball.

DJ Herz records his second 10+ K, 0 BB outing in 6 career starts! pic.twitter.com/fuVNhDscKT

— MLB (@MLB) July 3, 2024

Herz can improve by being more efficient with his pitches. Too many times last year, he found himself working deep into the counts; therefore, he did not work deep into the games because of his inconsistency in the strike zone. His 9.4 (29th percentile) walk percentage reflects that.

The bottom line is that he can generate swings and misses but needs to consistently fill up the strike zone and put hitters away. According to NFBC, Herz's ADP is 317.0, and fantasy managers looking to target a young, high-upside power pitcher should add him to their target list toward the end of drafts, though they may have to wait a little for him to crack the rotation.

Bubba Chandler, SP, Pittsburgh Pirates

Pittsburgh Pirates right-handed pitcher Bubba Chandler has the potential to be part of the Pirates starting rotation following a rock-solid 2024 minor league season. Last year, he had a 3.08 ERA, a 1.02 WHIP, and 148 strikeouts in 26 appearances (23 starts) across Double-A and Triple-A.

Chandler was drafted by the Pirates in the third round of the 2021 MLB Draft. He quickly moved through the minors and has succeeded at every level. Chandler has an elite fastball that averaged 96.7 mph and touched 99 mph in 2024, according to Synergy. Chandler also offers an 86-87 mph slider, a changeup in the upper 80s, and occasionally throws a curveball in the low 80s to go along with the electric fastball.

Bubba Chandler, MLB's No. 15 overall prospect, struck out a batter and touched 99.1 mph in one frame of work in his first Spring Training action this year.@Pirates | @YoungBucsPIT pic.twitter.com/6njjwLq7O0

— MLB Pipeline (@MLBPipeline) February 23, 2025

Perhaps all of the hype is because of the success we have seen with other young Pirates pitchers, like Paul Skenes and Jared Jones, both of whom Chandler has worked out with over the past year. But when you combine Chandler's performance in the minors with the Pirates rotation being fairly open after Skenes, Jones, and Mitch Keller, it seems like a matter of when, not if, Chandler joins the rotation in 2025.

According to NFBC, Chandler's ADP is 299.0, so most high-stakes drafts feel the same way. I am willing to take the late-round pick and find out, and you should, too.

Ryan Weathers, SP, Miami Marlins

Miami Marlins left-hander Ryan Weathers has been dazzling in spring training to start the season, throwing 7 1/3 innings with a 12.27 K/9 and a 1.23 ERA. During his recent outing, he touched 99 mph and looks healthy entering the 2025 season. Reports from camp say he also lost 20 pounds in the offseason.

With the departure of  Jesus Luzardo to the Philadelphia Phillies, Weathers will undoubtedly be counted on in the Marlins starting rotation behind right-hander Sandy Alcantara. The Marlins have been known to develop young pitchers, and Weathers, a former first-round pick in 2018, looks poised to break out this year and crush his ADP.

Weathers experienced some hard times in his first few seasons in the big leagues. In his first season (2021) at the MLB level, he threw 94 2/3 innings and had a 5.32 ERA. In August 2023, he was traded to the Marlins and looked better with them over the last couple of months of the season.

He began the 2024 campaign as a part of the Marlins rotation. In 2024, he went 5-6 with a 3.63 ERA, 4.11 FIP, and an 8.31 K/9. Weathers missed three months in 2024 with a left index finger strain, but he flashed his upside before the injury.

Ryan Weathers, 99mph ⛽️ pic.twitter.com/GMSkWHDQo9

— Rob Friedman (@PitchingNinja) March 11, 2025

Weathers mostly relies on four pitches: his four-seamer, changeup, sweeper, and sinker. He ranks in the 76th percentile in fastball velocity, 73rd percentile in walk percentage, and 76th percentile in ground-ball rate. That tells me he doesn't allow free passes and generates a lot of ground balls.

If we continue to see his velocity go up and he increases his strikeout and whiff percentage, Weathers could be a top-30 pitcher. According to NFBC, his current ADP of 351.0 makes him a steal. Fantasy managers should consider taking a late flier on him in 2025 drafts.

Joey Ortiz, 3B, Milwaukee Brewers

Milwaukee Brewers third baseman Joey Ortiz, who will be moving to shortstop this season, had a solid rookie year in 2024. He slashed .239/.329/.398 with 11 home runs, 60 RBI, 58 runs, and 11 stolen bases in 142 games.

Ortiz provides a lot of value because he has a good walk rate of 11 percent and plays solid defense (96th percentile in Range OAA), which should keep him in the lineup every day and provide consistent opportunities. For the 2025 season, ATC is projecting Ortiz to slash .248/.316/.392 with 12 home runs and a 2.0 WAR.

In addition, he keeps his strikeout rate respectable (20.2 percent) and ranks in the 76th percentile for bat speed and the 89th percentile for whiff percentage.

There is only ONE player in the Major Leagues right now that ranks in the 80th percentile or higher in walk rate, strikeout rate, sprint speed, and bat speed.

Joey Ortiz.#ThisIsMyCrewpic.twitter.com/O3dGpnhmnV

— Eric Cross (@EricCrossMLB) June 5, 2024

Although Ortiz does not provide anything flashy, he provides fantasy managers with a solid floor if they are looking for some late-round value at the infield position. With a full season of plate appearances, he can hit 20 home runs and steal 20 bases.

According to NFBC, his current ADP of 286.0 makes him a solid draft pick. Fantasy managers should consider taking a late flier on him in 2025 drafts.

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