Andrew Painter, Bubba Chandler and other top MLB prospects who could make big-league debut in 2025

Every Major League Baseball season follows a certain cadence. Once you become attuned to it, you come to know that March is reserved for Opening Day; that September is for playoff jockeying; that early July is for the amateur draft, and late July the trade deadline; and so on. There's been a new addition to that drumbeat in recent years, since the implementation of the current CBA and the forming of the Prospect Promotion Incentive guidelines: the wave of late-August debuts.

The Baltimore Orioles' recent promotion of catcher/first baseman Samuel Basallo signals that it's time for various top prospects across the league to realize their dream of reaching The Show --  not because they're suddenly ready for action, but because there's no longer a reason to hold off. 

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Mike Axisa

Indeed, there are now fewer than 45 days remaining in the regular season, which means that any player promoted for the first time will retain their rookie eligibility into next year -- provided, anyway, that they don't meet certain playing time requirements. Why does that matter? Because it means the game's top prospects will remain eligible to win next year's Rookie of the Year Award -- an achievement that, if realized, would in turn net their team an extra draft pick.

In other words, don't expect Basallo to be the only highly regarded youngster getting the call over the coming weeks. Here are four other top prospects worth keeping tabs on.

1. Andrew Painter, RHP, Philadelphia Phillies

Painter has been on the precipice for what feels like ages. He looked certain to debut in 2023 before undergoing Tommy John surgery that summer, an operation that effectively wiped out close to two years. He's spent this season in the minors, but his arrival could be imminent now that the Phillies are operating without Zack Wheeler (sidelined at present by a blood clot). In theory, Painter could slot into a six-pitcher rotation; that arrangement would allow him to get acclimated to the majors while limiting his workload (he's 10 innings shy of his career high).

Painter, 22, is a strapping right-hander with a broad, if atypical arsenal. Why atypical? Because his repertoire features more glove-side movement than you might expect from his high three-quarters release point. In addition to a mid-to-upper-90s fastball with at-times natural cut, he throws three other options that move away from right-handed batters: a cutter/slider, a sweeper, and a curveball. Painter also has a changeup he'll break out from time to time. All five of those offerings grade as above-average, according to some of the pitch-grade models out there, giving him an enticing top-of-the-rotation ceiling if he can stay healthy and refine his game.

If there's an argument to be made against Painter's promotion, it has to do with his recent results. On the season, he's amassed a 5.31 ERA and a 2.41 strikeout-to-walk ratio in 17 Triple-A starts. He's incurred a lot of damage since July, compiling a 6.37 ERA and an .861 OPS in his last eight outings. Blame those struggles on rust, fatigue, or some combination thereof; it's up to the Phillies to decide if they're OK stomaching whatever growing pains that a Painter promotion would entail. 

2. Bubba Chandler, RHP, Pittsburgh Pirates

Another talented right-hander who has been in the launch position all season. The Pirates still seem more likely than not to press the button and have Chandler debut before year's end, but you would be well within your rights if you were starting to wonder if he'll have to wait until 2026.

Chandler, 22, hasn't exactly knocked the door down with his production. He's sporting a 4.05 ERA and a 2.28 strikeout-to-walk ratio across 24 Triple-A starts. Those marks include a putrid three-start stretch in August that has seen him surrender 10 runs on 20 hits in 12 innings. Despite those woes, Chandler's future remains bright. His arsenal is led by a high-octane fastball that features both impressive velocity (97.8 mph on average) and rise from a sub-6-foot release height. He also has an above-average slider that has generated the best hard-hit percentage. 

It's clear that Chandler needs to make more adjustments to his game if he wants to fulfill his promise. What the Pirates have to figure out is whether exposing him to big-league competition over the next month would be favorable or harmful to his development. 

3. Bryce Eldridge, 1B, San Francisco Giants

The Giants have slipped far enough in the playoff race that they can justify prioritizing the future. Shifting their sightlines could entail, among other things, giving Eldridge the playing time that's currently earmarked for veteran and impending free agent Dom Smith. (That's not an intended slight to Smith, who is rocking a 115 OPS+ while splitting time with Rafael Devers.)

Eldridge, 20, has hit .236/.300/.497 with 12 home runs across 43 Triple-A games. Although a .797 OPS from a first baseman doesn't look impressive at first glance, it's worth noting that the affiliate average is just .733. Besides, Eldridge is smoking the ball: his average exit velocity is north of 94 mph, and nearly 60% of his balls in play have cleared the 95 mph threshold. 

Eldridge's game does feature a fair amount of swing and miss, and he's not been impressive against left-handed pitching. It's unclear if those are correctable blemishes; however, given that he's 6-foot-7 and that a lot of lefty batters take uncomfortable at-bats against southpaws. It's wholly possible that the Giants decide they can live with those flaws, provided he slugs like he can.

4. JJ Wetherholt, SS/2B, St. Louis Cardinals

Much of what applies to the Giants applies to the Cardinals. St. Louis is, too, far enough out of the playoff race to give in to the promise of tomorrow. At the same time, the ascent of the most likely promotion candidate (in this case, Wetherholt) is being impacted by a crowded depth chart. 

Wetherholt, 22, may well go down as the steal of the 2024 draft thanks to his athleticism and feel for hitting. (He entered the spring ranked No. 1 by CBS Sports but slipped to No. 7 after missing half his platform season because of a hamstring injury.) He's hit .310/.403/.670 with nine home runs and three stolen bases in 26 games since being promoted to Triple-A. To think, he's done that while seeing action across the infield so as to improve his optionality. 

The Cardinals just placed Brendan Donovan on the injured list, theoretically creating a spot for Wetherhold. They instead opted to bring up José Fermín, likely so that they could continue to give Thomas Saggese (yet another talented infielder) more steady at-bats. That's a reasonable decision, even if it doesn't completely shut the door on Wetherholt arriving before season's end.

At minimum, the Cardinals would be wise to sort through their other infielders -- Donovan, Saggese, Nolan Gorman, and Masyn Winn -- so that they have a better idea heading into the winter who is expendable and who else has a long-term home on their roster. They already know that Wetherholt does.