Here are the top 10 closer prospects in the Minors

May 1st, 2024

The role of the reliever continues to evolve in baseball, but there’s still something to be said about closers. They’re the ones who get the entrance music and the light show just for coming out of the bullpen in the biggest of spots. (Think of what Edwin Díaz has done for the popularity of the trumpet in this country since he incorporated “Narco” into his routine.) And the market has proven how much it values the best relief arms with Díaz and Josh Hader signing five-year deals worth $102 million and $95 million respectively in recent offseasons.

Who could be the next big arms called upon for high-leverage situations in The Show? Here are MLB Pipeline’s Top 10 closer prospects currently in the Minor Leagues.

1. Hurston Waldrep, RHP (ATL No. 2, MLB No. 82)
Waldrep was last used as a true reliever as a freshman at Southern Mississippi before transitioning to starting roles there and at Florida, and the Braves drafted him 24th overall as a potential starter last July. But control problems continue to follow the 22-year-old, in part due to a high-tempo delivery, and those haven’t stopped this season at Double-A Mississippi (10 walks in 19 innings). Waldrep’s splitter is one of the best of its kind in the Minors, and his upper-80s slider has gotten strong whiffs in his early outings in 2024. Those two pitches, along with a mid-90s fastball, could play up in shorter stints, and given Atlanta’s win-now mode, the organization could prefer to use Waldrep’s high-quality stuff quickly. Of note, 34-year-old closer Raisel Iglesias becomes a free agent after the 2025 season, so a succession plan can’t be far off.

2. Reggie Crawford, LHP (SF No. 8)
While talking to's Jim Callis last autumn, one Giants official compared Crawford to a left-handed Paul Skenes, noting his fastball can touch triple digits while his mid-80s slider gets depth and a healthy amount of whiffs. The 2022 30th overall pick is perhaps most famous for his two-way status coming out of UConn, but Tommy John surgery and myriad other injuries (most recently a strained lat) have slowed his progress. San Francisco is committed to keeping Crawford on the mound and has used him as a reliever out of the gate at Double-A Richmond this spring. So long as he stays healthy, the 23-year-old’s heater-slider combo could devastate the upper Minors in a limited role and push his way to the back end of the Bay Area bullpen.

3. Landon Sims, RHP (AZ No. 23)
Sims already has a background as a dominant closer. He saved 13 games and struck out 100 batters in 56 1/3 innings for Mississippi State’s championship-winning team in 2021. He was moving to the Bulldogs rotation in 2022 when he needed Tommy John surgery just before the Draft, where he was taken 34th overall by the D-backs. The 6-foot-2 right-hander made 15 appearances in his pro debut last year and is back in the Single-A Visalia bullpen this spring. Arizona officials have been pleased with the 23-year-old’s fitness level after a healthy offseason, and he has the mid-90s fastball and wipeout slider that work especially well in relief. Even if he dabbles with starting again, Sims’ closing experience on big stages can’t be overlooked and could be a deciding factor in pushing his two-pitch mix into Arizona’s relief corps.

4. Jarlin Susana, RHP (WSH No. 10)
Incredible fastball? Check. Susana can touch as high as 103 mph and regularly sits right under triple digits. Solid breaking ball? Check again. The 20-year-old’s upper-80s slider can draw whiffs against anyone sitting heater. Control problems? Well, those are there too. Susana has walked 64 batters in 120 1/3 innings between the Padres and Nationals systems. Washington would like to keep the 6-foot-6 hurler in a starting role for as long as possible, but all the markers are there for a classic high-octane arm out of the bullpen, where Susana can truly let the ball fly.

5. Andrew Walters, RHP (CLE No. 25)
Here’s a fun fact: Walters had more saves (26) than earned runs allowed (16) over his three years at Miami. The former Hurricane was at his most dominant as a junior in 2023, posting a 1.21 ERA with 72 strikeouts in 44 2/3 innings, and Cleveland picked him up as the 62nd overall pick in July. The Guardians sent the 6-foot-4 right-hander straight to Double-A Akron, and he’s dominated there as well with one earned run, 22 strikeouts and three walks in eight games (10 innings). Walters’ mid-90s fastball gets good ride and plays up with deception, and his low-80s slider can get whiffs too, though he relies heavily on the fastball. It’s an approach that’s served him well so far and could put him on the fast track to The Show.

6. Marc Church, RHP (TEX No. 22)
Church got a long look in Texas’ Major League camp this spring and might have already gotten the callup to the bigs if not for a shoulder strain that currently has him sidelined. The 23-year-old right-hander’s mid-90s fastball comes with tons of carry, and he can manipulate the shape of his slider to be longer or shorter based on need, making it another potential plus-plus offering. With a 34.7 percent career K rate, Church has shown he can blow by hitters and has the two-pitch profile and stuff to carve out a prominent relief role, even if his control is below average.

7. Patrick Reilly, RHP (PIT No. 22)
Reilly had opportunities to start at Vanderbilt but never quite stuck in that role. The Pirates still drafted him as a potential starter in last year’s fifth round, and early results (particularly 29 K in 16 2/3 IP) at High-A Greensboro have been promising. But the fact remains that Reilly’s high-effort over-the-top delivery still points to a future in the bullpen. He can get ride up in the zone on his 95-99 mph fastball, and his mid-80s slider could be even more dangerous in shorter stints. Much will come down to Reilly’s ability to find the strike zone, but the raw materials for an exciting arm are there.

8. Zach Maxwell, RHP (CIN No. 27)
Maxwell can be a polarizing prospect. On one hand, he’s 6-foot-6 with a fastball near triple digits and an upper-80s curveball that many hitters can’t touch. Those pitches helped him punch out 96 batters in 61 1/3 innings between Single-A and High-A last season and have earned him 14 punchouts through 7 1/3 Double-A frames to open 2024. On the other hand, he averaged a walk per inning during his time at Georgia Tech and may have only recently made the proper targeting adjustments to improve his control. If these hold, Maxwell very well could see Cincinnati by late summer, if not earlier.

9. Jaden Hill, RHP (COL No. 27)
Elbow and shoulder issues limited Hill both in college and the pros, and this season, the Rockies did what seemed inevitable by moving the 24-year-old to the Double-A bullpen. Unlike others on this list, Hill has the potential for three above-average pitches in his upper-90s fastball, mid-80s changeup and mid-80s slider, giving him a leg up on other relievers. Health can’t be guaranteed, however, and it might take Hill showing he can stick on the mound, even with relief restrictions, for him to meet his closer ceiling.

10. Antoine Kelly, LHP (TEX No. 21)
The defending World Series champs have two prospects on this list. Kelly is a pure relief prospect with a 95-97 mph fastball that plays up because of a deceptive three-quarters delivery and a mid-80s sweeping slider that hitters also have difficulty reading. He earned 11 saves last season at Double-A Frisco in his first season fully in the bullpen and finished with a 1.95 ERA and 69 strikeouts in 50 2/3 frames in the Texas League. Like Church, Kelly is on the Triple-A IL with a shoulder issue, but once both are healthy, the competition for a big role in Arlington will be on.