5 Undervalued Hitters and Fantasy Baseball Waiver Wire Adds - Players Outperforming Their Rostership

May 8, 2025

Lauren examines 5 fantasy baseball waiver wire pickups, sleepers and trade targets for Week 6 - undervalued hitters outperforming their rostership and should be more widely owned.

In every fantasy baseball season, a handful of hitters quietly outperform expectations while remaining surprisingly under-rostered.

Players like Kyle Stowers, Maikel Garcia, and Jacob Wilson have cracked the top 100 rankings, yet still fly under the radar in many leagues. Even deeper cuts like Trent Grisham and Ryan O'Hearn are putting up numbers that suggest they deserve more attention.

So why aren’t these players more widely rostered? Are they simply riding short-term hot streaks, or do they offer real long-term value? It’s time to take a closer look at these undervalued hitters and assess whether now is the moment to add them to your roster.

Trent Grisham, OF, New York Yankees

25% rostered

Grisham hit his ninth home run of the season -- and his fifth in his last 11 PAs -- on Monday vs. the Padres at Yankee Stadium. And then he hit another home run on Wednesday, his 10th of the year. He's now second on the team in homers behind Aaron Judge, who has 11. So, why is he only 25% rostered?

Trent Grisham's strong start continues 💪 pic.twitter.com/c6xB8w7AeR

— MLB (@MLB) May 6, 2025

At 28, we know by now the type of hitter Grisham is. And, for most of his career, he's been below average. He has a .217 BA entering his seventh season in the league, and hasn't been able to put it all together at the MLB level after being a first-round pick of the Milwaukee Brewers in 2015. Grish set a career-high in homers in 2022 with 17, but had a .625 OPS across 152 games. If he keeps going at his current rate, though, he'll surpass that previous mark.

Grisham has achieved his 2024 HR total in 116 fewer at-bats -- producing a 92 average exit velocity -- and has nearly doubled his fWAR from 0.5 last season to 1.1 in 2025. Outside the homers, though, Grisham hasn't done much. Of his 10 XBH, nine are home runs, with a double on April 3. His .298 BABIP indicates he is making good contact but not getting lucky with batted balls, and he's also struck out 18 times.

So, the question for fantasy managers is: are the home runs worth it? Grisham's high home run to fly ball rate and overall track record suggest his offensive output isn't sustainable. He is still in line for a career year, and taking advantage of his luck could prove beneficial to fantasy lineups.

Ryan O'Hearn, 1B/OF, Baltimore Orioles

21% rostered

In only three games this month, O'Hearn has totaled 12 bases, adding a double, two homers, and three RBI, bringing his season average to .306 and his OPS to .979. The 31-year-old crushed it across a three-game series against his former team, the Kansas City Royals, for whom he produced a -2.6 WAR in five seasons. O'Hearn was traded for cash to the Orioles in January 2023. He's made them pay since.

Ryan O'Hearn powers one to center for the lead 💥 pic.twitter.com/2hGG3KGGIg

— MLB (@MLB) May 3, 2025

Perhaps O'Hearn's track record is why he's just 21% rostered. He's also on the wrong side of 30 and doesn't play every day. But his success in Baltimore has been noticeable. O'Hearn has accrued 4.1 WAR and slashed .278/.334/.465 with 36 homers in 279 games with the O's. He's just two HRs shy of matching his total with the Royals (38). So, what gives? What more does O'Hearn have to do to see an uptick in his rostered percentage?

Keep hitting homers, sure, but by now, fantasy managers should be familiar with O'Hearn's game. He's inconsistent; he'll have incredible offensive stretches followed by lackluster slumps. And at this point in O'Hearn's career, there's not much more to uncover about him as a ballplayer. He can supply you with the occasional hot streak, but he's not a long-term option. O'Hearn will regress to the mean eventually.

Kyle Stowers, OF, Miami Marlins

58% rostered

Stowers may have already been on the radar of fantasy managers due to his hot start to the season for Miami. However, his walk-off grand slam on May 3 off of Athletics flame-throwing closer Mason Miller -- for his second homer of the game -- made him somewhat highly coveted on the waiver wire.

WALK-OFF GRAND SLAM 🚨

KYLE STOWERS SENDS 'EM ALL HOME 🔥 pic.twitter.com/em550A2b1j

— MLB (@MLB) May 3, 2025

Per Yahoo Fantasy, the 27-year-old currently ranks 46th but is only 58% rostered. Stowers is a former prospect of the Baltimore Orioles who joined the Marlins at the 2024 trade deadline along with Connor Norby, who's also found offensive success with the Fish. Stowers, who was just named National League Player of the Week, is slashing .310/.380/.522 with 11 extra-base hits, 25 RBI, and 13 walks in 129 plate appearances this year, but isn't even 60% rostered.

The simple reason could be Stowers' track record. He's a career .235 hitter with a .682 OPS, and with Baltimore, he struggled to stick at the major league level. It's understandable why fantasy managers are cautious to add him. That said, perhaps Stowers getting to play every day has helped awaken his bat.

He's serving a key role in Miami, an opportunity that wasn't possible with the O's and their plethora of big-name prospects. Plus, the underlying numbers are on his side, ranking in the 86th percentile or above in multiple categories, including bat speed, hard-hit percentage, barrel percentage, xSLG, xBA, and xwOBA. Although with a .408 BABIP, this pace probably isn't sustainable, he still has long-term potential to be a solid hitter.

Jacob Wilson, SS, Athletics

47% rostered

The Athletics are employing a youth movement in Sacramento this year. Among the youngsters is 23-year-old Jacob Wilson, son of former major leaguer Jack Wilson. Jacob was the sixth overall pick of the A's in the 2023 draft and made his MLB debut in July 2024.

Jacob Wilson delivers his second #walkoff hit of the season! pic.twitter.com/WLJUb3A9x4

— MLB (@MLB) May 6, 2025

In the 239 PAs that have followed, Wilson has a career .302 BA and .342 OBP, with 13 walks to 16 strikeouts. However, only 13 of his 67 career hits have gone for extra bases. Wilson has six doubles, three homers, and 18 RBI this season, showing that perhaps he is on the upswing. It's important to remember that he's still under 25 and has just 62 big league games under his belt. He has plenty of time to develop his power stroke further.

Maybe his lack of power keeps fantasy managers from adding him. Wilson ranks 73rd and is 47% rostered. Still, his on-base skills are there, and he can be a serviceable piece to any lineup. Wilson certainly has long-term potential given his age and lack of MLB experience, leaving plenty of room for future growth.

Maikel Garcia, 2B/3B, Kansas City Royals

72% rostered

Bobby Witt Jr. understandably gets all of the attention in Kansas City, leading the Royals in most offensive stats -- not in average or on-base percentage, though. Those belong to Garcia, who owns a .322 BA and .390 OBP through 136 PAs this season.

Players with a multi-homer game and 2 games with multiple stolen bases through their first 5 games played in any month in the modern era (since 1901).

Maikel Garcia May 2025
Shohei Ohtani May 2024 pic.twitter.com/iFdnvuXKVJ

— OptaSTATS (@OptaSTATS) May 6, 2025

The 25-year-old third baseman has four homers, 15 RBI, nine stolen bases, and a .886 OPS on the season, but ranks 37th and is 72% rostered. Fantasy managers are finally noticing Garcia's surge; his rostered percentage has climbed 16% in the last week. Considering he's batting .500 and slugging .808 in that span, it's expected. But how serviceable will Garcia be beyond that?

Garcia's batted-ball profile is a sea of red. He's hitting the ball hard and doesn't chase or strike out a lot. On the flip side, he's not barreling the ball much and has achieved an above-average OBP while not walking that often, which is a testament to his bat-to-ball skills. Moreover, Garcia has been a wishy-washy player since his debut in July 2022, with a .670 career OPS.

However, with the significant improvement of his underlying numbers, Garcia may have turned a corner offensively, where he is more consistent. If this is the case, he could be a long-term option for fantasy managers.

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