MLB Prospect Debuts: Fantasy Baseball Waiver Wire Pickups and Rookie Stashes (Week 4)

Frank's fantasy baseball prospect stashes, sleepers and rookie waiver wire pickups for Week 4 of 2025 - recent MLB prospect debuts and potential call-ups to monitor.

We're almost a whole month into the 2025 MLB season, and we already have several prospects who have been recalled to make their big league debuts. Rookies can help boost your fantasy baseball teams, so it's important to always monitor the latest MLB prospects.

In this article, we'll go through several notable prospects who have been recalled, such as Chandler Simpson, Luke Keaschall, and Nick Kurtz. You'll also read about a few prospects who could be on their way soon, including Roman Anthony, Bubba Chandler, and Zebby Matthews.

Remember to always temper your expectations, since even the best prospects can struggle at times. Just look at Jackson Holliday with the Baltimore Orioles. With that in mind, let's take a closer look at which MLB rookies should be on our radar for fantasy baseball.

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Fantasy Baseball Prospects To Target

The following rookies have already been recalled to the big leagues. If they're available in your league, it's a good idea to pick them up if you have space on your roster. For each player, you'll find their minor-league stats for the season along with their fantasy outlooks.

Chandler Simpson, OF, Tampa Bay Rays

Status: Called Up
2025 stats: 78 PA, .301/.325/.329, 13 R, 0 HR, 8 RBI, 8 SB, 3.8 BB%, 9.0 K%, 76 wRC+

Chandler Simpson has two runs, two RBI, and two stolen bases in 15 plate appearances since being recalled to the Rays on April 19. During this stretch, Simpson has hit in the leadoff spot in two of four games. This is a player who racked up 73 steals in 358 plate appearances at Double-A last year. While there's immense stolen base upside, he's going to hurt you in home runs and RBI. Make sure that you can afford the hit in power if you're rostering Simpson.

Nick Kurtz, 1B, Athletics

Status: Called Up
2025 stats: 97 PA, .321/.385/.655, 18 R, 7 HR, 24 RBI, 0 SB, 10.3 BB%, 26.8 K%, 144 wRC+

Nick Kurtz went 1-for-4 with one RBI in his debut with the Athletics, batting seventh in the lineup. This is a polished hitter with strong plate discipline, so there's a good chance that he can make an immediate impact. You also have to love that Kurtz will get an opportunity to hit in the bandbox that is Sutter Health Park. Kurtz receives a bump in OBP formats due to his double-digit walk rates throughout his time in the minors.

"Nick Kurtz, welcome to Major League Baseball!"

The @Athletics top prospect gets his first hit and RBI in his first MLB at-bat. pic.twitter.com/zidF3WlBnD

— MLB (@MLB) April 24, 2025

Luke Keaschall, 2B, Minnesota Twins

Status: Called Up
2025 stats: 58 PA, .261/.379/.348, 8 R, 1 HR, 5 RBI, 4 SB, 15.5 BB%, 19.0 K%, 102 wRC+

Luke Keaschall has put up four R, two RBI, and five SB in 22 plate appearances with the Twins so far. The most notable number is the stolen bases, as he has been running wild on the base paths so far. This is a trend that has carried over from Triple-A, as he had four steals in only 58 PA. With Keaschall's plate discipline skills, the versatile player (eligible at 1B, 2B, OF in Yahoo!) can help out your team, especially in OBP formats.

Agustin Ramirez, C, Miami Marlins

Status: Called Up
2025 stats: 80 PA, .254/.313/.479, 13 R, 3 HR, 12 RBI, 5 SB, 8.8 BB%, 23.8 K%, 113 wRC+

Agustin Ramirez has one R, one RBI, and one SB in eight PA with the Marlins since being recalled. What's intriguing here is the rare speed for a catcher, as he racked up 22 steals across all minor league levels last season. It's also a good sign that Ramirez has yet to strike out in the big leagues. The former Yankees prospect and jewel of the Jazz Chisholm Jr. trade is a must-add in two-catcher leagues. If you have a fringe catcher in 1-C formats, I'd make the move as well, as it's best to chase upside.

111 MPH off the bat and Agustín Ramírez is now 5-6 to start his big league career. pic.twitter.com/6CgxgjpjUf

— Marlins Radio Network (@MarlinsRadio) April 23, 2025

Caleb Durbin, 3B, Milwaukee Brewers

Status: Called Up
2025 stats: 58 PA, .278/.316/.481, 12 R, 2 HR, 3 RBI, 3 SB, 5.2 BB%, 8.6 K%, 115 wRC+

Caleb Durbin has put up four R, one HR, three RBI, and one SB in 25 PA with the Brewers so far. This is an infielder with a good hit tool who can be an asset in batting average while also contributing in speed (31 SB in 406 PA in minors last year). While there's not much power here -- 10 HR across all minor league levels in 2024 -- Durbin can be a valuable contributor if you need BA+SB. It also helps that he will gain 3B eligibility to go along with 2B.

Ben Williamson, 3B, Seattle Mariners

Status: Called Up
2025 stats: 60 PA, .281/.317/.333, 6 R, 0 HR, 8 RBI, 2 SB, 3.3 BB%, 15.0 K%, 71 wRC+

Ben Williamson has posted seven R, one HR, and three RBI in 31 PA with the Mariners. The only thing here is that there's not much power, as Williamson homered only four times in 541 plate appearances in the minors last season. The good news is that he can provide rare speed for a third baseman, as highlighted by his 19 SB in 2024. This is a deep-league pickup who should only be rostered if you're desperate at 3B or CI.

Fantasy Baseball Prospects To Monitor

The next group of prospects includes players who are still in the minors. The expectation is that each of these prospects will be up in the big leagues before the end of the season. Each of these rookies can make a major impact on your fantasy baseball teams, but they're best rostered in leagues where they can be stashed in an NA spot.

Roman Anthony, OF, Boston Red Sox

Level: Triple-A
2025 stats: 94 PA, .297/.436/.554, 17 R, 4 HR, 13 RBI, 2 SB, 20.2 BB%, 22.3 K%, 167 wRC+

Roman Anthony is widely considered to be the top prospect in baseball. The Red Sox outfielder has torn it up in the minors at a young age, as he's still only 20 years old. The issue here is there's a logjam in the outfield for Boston. Wilyer Abreu is having a strong start, while Ceddanne Rafaela is an elite defender in center, and Jarren Duran is entrenched in left field. With that said, Anthony's bat may force its way into the lineup sooner rather than later.

That’s my left fielder right there. Roman Joseph Anthony. pic.twitter.com/WAjxJOnU5C

— Jared Carrabis (@Jared_Carrabis) April 23, 2025

Bubba Chandler, SP, Pittsburgh Pirates

Level: Triple-A
2025 stats: 15.1 IP, 1.76 ERA, 0.78 WHIP, 41.1 K%, 10.7 BB%, 2.41 xFIP

Bubba Chandler is the best pitching prospect in MLB right now, as highlighted by impressive strikeout numbers in the minors, including this year's 41.1 K percentage. It's only a matter of time before Chandler joins the Pirates' rotation. Expect Pittsburgh to slow-play their young pitcher just like they did with Paul Skenes last season. The Pirates didn't call up Skenes until May 11, which feels like a reasonable projection for Chandler's arrival.

Pirates prospect Bubba Chandler so far in 2025:

6.2 IP, 2 H, 0 R, 12 K 🔥 pic.twitter.com/48zHctWSnJ

— MLB (@MLB) April 9, 2025

Jordan Lawlar, SS, Arizona Diamondbacks

Level: Triple-A
2025 stats: 102 PA, .333/.426/.632, 21 R, 5 HR, 22 RBI, 8 SB, 157 wRC+

Jordan Lawlar has gotten off to a scorching start in Triple-A, leading many to believe that a callup is imminent in the near future. The issue here is that Geraldo Perdomo has played well at shortstop, while Ketel Marte may be able to return at second base earlier than expected. However, if Lawlar continues to perform at such a high level in the minors, the D-Backs may have no choice but to call him up.

Zebby Matthews, SP, Minnesota Twins

Level: Triple-A
2025 stats: 18.2 IP, 1.45 ERA, 1.02 WHIP, 32.4 K%, 4.1 BB%, 2.67 xFIP

Zebby Matthews has consistently demonstrated elite control throughout his minor league career. While fellow prospect David Festa has pitched well, there's still room for Matthews to join the rotation, as Chris Paddack and Simeon Woods Richardson have both struggled this year. However, we may have to wait a little longer since Pablo Lopez is expected back soon. Even still, it's worth stashing Matthews given his impressive minor-league numbers.

More Fantasy Baseball Prospects and Rookies