Hot MLB Prospects to Watch for Fantasy Baseball - Week 5 (2025)

Andersen looks at the top fantasy baseball prospects risers, sleepers for Week 5 of 2025. These MLB prospects may become strong waiver wire stashes or pickups.

Welcome back, RotoBallers! The 2025 Minor League Baseball season is in full swing. During last week's action, there were plenty of big plays and impressive prospect performances throughout Minor League Baseball.

Monitoring the top fantasy baseball prospects who have turned heads thus far is imperative. The players listed here are coming off dominant weeks and have significant long-term upside. Don't be surprised when these exact names are painting corners, mashing homers, and swiping bags at the big league level soon.

Savvy fantasy managers looking for an edge in their leagues should watch these players over the long haul, as they may soon be excellent additions.

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Marcelo Mayer, SS, Boston Red Sox

Level: Triple-A
2025 stats: 23 G, .280/.324/.548, 7 HR, 34 RBI, 17 R, 1 SB, 6.9% BB%, 19.6% K%, .279 BABIP, .376 wOBA, 125 wRC+

Mayer is a former first-round pick off to his hottest start ever. He has looked good in the minors before, but injuries have hindered his ability to produce consistently. So far this season, though, he has stayed healthy while excelling at the plate and in the field.

Offensively, Mayer possesses an advanced swing and knows the strike zone. His power has consistently been on display, and he has a chance to be one of the best power-hitting middle infielders in pro baseball. He rounds out his skill set with excellent defense. Mayer can stick at shortstop long-term, but he could also survive a shift to second or third base.

Last week, Mayer went 9-for-20 with three home runs, 12 RBI, three walks, and four strikeouts. Boston has a logjam of talent at the major league level, but Mayer is still pushing for a roster spot with the Red Sox. He should debut sometime in May, and he looks like he could be an everyday player with all five tools.

Marcelo Mayer has been named the International Player of the Week.

6 Games
25 PA
.450/.480/1.050/1.530
3 HR
3 2B
12 RBI
266 wRC+

Mayer is up to 34 RBI in 23 games. That leads all of MiLB. pic.twitter.com/dWzmWaWvOr

— Tyler Milliken (@tylermilliken_) April 28, 2025

Jacob Misiorowski, SP, Milwaukee Brewers

Level: Triple-A
2025 stats: 6 G, 5 GS, 1-0, 29.2 IP, 1.82 ERA, 3.08 FIP, 11.53 K/9, 3.94 BB/9, 0.61 HR/9, 41.7% GB%, .200 BABIP

If you have stayed up to date with this series over the last few years, Misiorowski should be a very familiar name. He has been the fastest and most impressive riser among minor league pitchers, blossoming from a mid-tier prospect into one of baseball's best young arms.

Misiorowski has one of the best fastballs in affiliated ball, sitting in the upper 90s with the ability to touch north of 100 mph. He also throws a curveball and a cutter, both of which generate impressive movement. Control-wise, Misiorowski locates his heater nicely, but the breaking balls are a little less consistent, missing the zone a bit too much and sometimes failing to induce swings outside of the zone.

Misiorowski made two starts last week, and both were impressive. On Tuesday, he went six innings with zero runs, one hit, one walk, and eight strikeouts. Five days later, he returned to the mound and delivered five shutout innings with three hits, zero walks, and nine strikeouts. All in all, he struck out 17 batters over 11 scoreless frames. He is quickly closing in on his MLB debut.

Jacob Misiorowski cooked up an International Pitcher of the Week award with two incredible starts! 🏅

4/22: 6.0 IP / 1 H / 0 R / 1 BB / 8 K
4/27: 5.0 IP / 3 H / 0 R / 0 BB / 9 K#ThisIsMyCrew pic.twitter.com/hvpa4x848j

— Brewers Player Development (@BrewersPD) April 29, 2025

Francisco Acuna, SS, San Diego Padres

Level: Double-A
2025 stats: 18 G, .293/.354/.533, 5 HR, 15 RBI, 13 R, 5 SB, 6.0% BB%, 26.5% K%, .354 BABIP, .399 wOBA, 152 wRC+

Acuna, a former Pirates prospect out of Colombia, reached minor league free agency last winter and signed with the Padres. At 25 years old, he's on the older side for a Double-A prospect, but his age hasn't hindered his ability to turn in a hot start at the plate.

Acuna is launching the ball very well and, as a result, is already just one home run away from his single-season best. Shrinking his K/BB rate could truly elevate his game to the next level. Defensively, he runs well and will have a chance to stay at shortstop going forward. However, he also has significant experience playing second and third base, so he could survive a position change if needed.

Currently the owner of an 11-game on-base streak, Acuna is coming off a hot week at Double-A. Through six games, he went 10-for-22 with four homers, 10 RBI, three walks, and four strikeouts. He also stole a base in back-to-back contests.

Colombian SS Francisco Acuña has been one of the best stories of the minor league season in AA. He has an .888 OPS and has homered in 5 of his last 6 games. He had 13 HR in 347 games in his minor league CAREER before this season. He’ll likely be Colombia’s starting SS at WBC pic.twitter.com/Tw205L50js

— Jeff Duda (@INTLBaseball24) April 27, 2025

Hunter Barco, SP, Pittsburgh Pirates

Level: Double-A
2025 stats: 5 G, 5 GS, 1-0, 20.2 IP, 0.00 ERA, 1.65 FIP, 13.06 K/9, 1.74 BB/9, 0.00 HR/9, 54.1% GB%, .237 BABIP

Barco, a former Florida Gator, was the Pirates' second-round pick in 2022. The talented southpaw made a pair of appearances at Double-A last summer, but his season was cut short due to a stress reaction in his left tibia, and he remained in Altoona to open the 2025 season.

He throws a mid-90s fastball, pairing it with a slider and splitter. Barco is capable of using his low arm slot to get plenty of horizontal movement on the slider, allowing it to miss bats. His splitter can induce plenty of strikeouts, too.

In his latest outing last Sunday, Barco struck out eight batters over three scoreless innings. He allowed just one hit along the way. These numbers are impressive, and it will be fascinating to see if his extremely high K/BB rate is sustainable as the Pirates allow Barco to pitch deeper into games post-injury. Oh, and he has also gone 20.2 innings without allowing a run this season, so there's that.

I’ve been hyping up Hunter Barco since he was drafted and it’s finally paying off 🥹

After his scoreless outing today -

Season:
5 games
20.2IP
0.00 ERA
30 SO’s

Yes - NO. RUNS. ALLOWED. THIS. SEASON. Incredible

Top 100 prospect. Now.

pic.twitter.com/VwDacnZMpn

— Christian ✞ (@CWolfPGH) April 27, 2025

Leodalis De Vries, SS, San Diego Padres

Level: High-A
2025 stats: 17 G, .258/.324/.530, 3 HR, 13 RBI, 9 R, 2 SB, 9.5% BB%, 20.3% K%, .286 BABIP, .387 wOBA, 130 wRC+

De Vries signed with the Padres as one of the best international free agents in 2024, and it didn't take long for him to emerge as one of baseball's top overall prospects. He was solid at the Single-A level last season and has continued to perform quite well through the early portion of the 2025 High-A season.

The 18-year-old is a switch-hitting shortstop with five-tool potential. He makes solid contact from both sides of the plate, and his power makes him a threat to do a lot of damage. On top of that, he hasn't sacrificed plate discipline as much as we see from other power hitters. Defensively, De Vries uses his athleticism and elite arm strength to make challenging plays. He'll get a chance to stick at shortstop, but he could be a candidate to play third base.

This past week, De Vries went 7-for-20, and five of those hits came in one game. He went 5-for-5 last Tuesday, racking up 14 total bases as he hit for the cycle. He homered twice in that contest, driving in eight runs along the way.

"Leo De Vries is inevitable, my goodness!"

MLB's No. 17 prospect (@Padres) completes his first professional cycle (5 H, 8 RBIs) with a triple off the wall for the High-A @TinCaps: pic.twitter.com/Kt8WpcdAmt

— MLB Pipeline (@MLBPipeline) April 23, 2025

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