Champ or Chump: Lucas Erceg and Coby Mayo Fantasy Baseball Outlooks

MLB's trade deadline was a week ago today. Roles are still unsettled, and talented players will receive their first opportunity. This will probably be the last chance for fantasy managers to add impact talent off waivers until September call-ups.

Lucas Erceg was traded from the A's to the Royals, and he doesn't have a fantasy-friendly role in Kansas City... yet. Meanwhile, the Orioles shuffled their roster and called up two big prospects: Jackson Holliday and Coby Mayo. Mayo is a name that should be on the fantasy radar.

Without further ado, let's find out what these two players offer in fantasy.

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Lucas Erceg (RP, KC) 8% Rostered

Erceg has pitched to a 3.46 ERA over 39 IP this season, and he's deserved that mark no matter which ERA estimator you trust most. His xERA is 3.59, his FIP is 3.30, and his xFIP is 3.41. He also has three saves on the year, though they all came in Oakland.

Erceg isn't a household name, but his strikeout stuff is real. He has a 27.0% K% against an 8.0% BB% and features a legitimate four-pitch mix: fastball, slider, sinker, and change. His fastball is probably his best pitch. It averages 98.5 mph, within the 99th percentile of all MLB pitchers. It gets Erceg ahead with a 56.6% Zone% and puts opposing hitters away with a 13.2% SwStr%. His sinker works similarly with a 9.4% SwStr% and 54.3% Zone%.

Erceg's slider has more vertical break than horizontal break, and posts underwhelming strikeout indicators: 12.8% SwStr%, 41.1% Zone%, and a 31.3% chase rate. Still, hitters have struggled against it to the tune of a .186/.304/.322 line. Erceg's change is a work-in-progress with a 46.3% Zone% and 16.3% SwStr% but a 33.3% chase rate and a .391/.440/.696 slash line against.

Erceg is 29 years old but didn't start pitching full-time until 2022, so it makes sense he's still learning. Kansas City is also an ideal landing spot for him. The Royals lead MLB with 35 Outs Above Average as a team, while the A's rank last at -35. The superlative defensive support should help Erceg outpitch his peripherals moving forward.

Likewise, Kansas City's closer job is wide open. James McArthur is the current closer, but his 16.8% K% and 5.32 ERA aren't closer material. Hunter Harvey has received closing opportunities too, and his 4.44 ERA is better than McArthur's. However, he had a 6.97 ERA in June (10.1 IP), an 8.00 ERA in July (9.0 IP), and a 9.00 ERA so far this month (2.0 IP).

Erceg is easily the best pitcher in this bullpen, he has late-inning experience, and Kansas City is in the thick of the playoff hunt. They'll make the switch sooner than later, and Erceg will become a Champ in fantasy.

Coby Mayo (3B, BAL) 33% Rostered

Few scouts question Mayo's bat even if they have concerns about his glove. The fourth-round draft pick in 2020 climbed to No. 15 on MLB Pipeline's top-100 prospects list and No. 12 on the FanGraphs list before his MLB debut. He doesn't have a hit yet, but look at his scouting reports:

Both scouting reports see a slightly below-average hit tool that his massive power more than makes up for. Mayo's MiLB resume supports the power, but his hitting tool looks better than the scouts expected.

Mayo first reached the high minors with Double-A (Bowie) in 2022, slashing .250/.331/.398 with five homers in 145 PAs. His 34.5% K% looked alarming, but his 11.3% SwStr% wasn't bad for a 20-year-old at Double-A and his 8.3% BB% was promising.

Mayo returned to Bowie in 2023 and conquered the level, hitting .307/.424/.603 with 17 HR and four steals over 347 PAs. His SwStr% declined to 10.2%, helping Mayo trim his K% to 24.8%. He also refined his eye, walking in 14.7% of his PAs. He even added considerable loft to his swing, increasing his FB% (36% to 40.5%) and LD% (20% to 24.5%).

The performance punched Mayo's ticket to Triple-A (Norfolk), where he hit .267/.393/.512 with 12 HR and a steal in 267 PAs. His SwStr% held steady at 10.5% despite facing more advanced competition, leading to a solid 23.2% K%. His 25% chase rate also suggested an advanced understanding of the zone and helped produce an exceptional 15.7% BB%. Mayo's added loft stuck with a 40.6% FB% and 23.9% LD% as well.

Mayo returned to Norfolk for the 2024 campaign and performed even better, hitting .301/.375/.586 with 20 HR and four steals in 341 PAs. His 10% BB% wasn't as high as the previous year, but his 25.5% chase rate was virtually unchanged. His 12.1% SwStr% contributed to a 24.3% K%, but a few extra strikeouts were a small price for a power uptick.

Mayo increased his FB% to 46.3% while his LD% held steady at 23.8%. Better yet, Mayo meaningfully cut down on pop-ups. In 2023, he had an IFFB% of 28.6%. This year, his IFFB% is 17.2%. You need to halve MiLB IFFB% marks to get a major league equivalent since the stat is calculated differently on the farm, and Mayo seems to have nipped a potential issue in the bud.

Mayo's HR/FB consistently hovers around 20%, so the power in his scouting report is showing up in games. However, this author fails to see a below-average hit tool. Swing-and-miss hasn't been an issue for him at any level, and he's posted above-average LD% rates since 2023 (roughly 950 PAs). Mayo's plate discipline is a strength, so poor swing decisions shouldn't adversely affect him. He even has a 50% Sweet Spot% in his first three MLB games.

Mayo was only successful on 50% of his SB attempts this season, so fantasy managers shouldn't count on any steals from him. The Orioles haven't given their top prospects much of a leash this season, so there is some risk he goes back to Norfolk if he gets off to a slow start. He's hit eighth in each of his first three games, and Baltimore even pinch-hit for him once. Still, Mayo's upside and likelihood of reaching it are too great to ignore.

Scouts may not like the look of Mayo's swing, but all available evidence suggests it gets the job done. He knows how to elevate the baseball, is willing to take a walk, and has 30 HR upside over a full season. Mayo is a Champ who should be rostered in all formats.

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