We’re about to hit the stretch run in the big leagues and all 30 teams will expand their rosters in September to help get through the regular season’s final month. Whether it’s one of 15 teams within four games of a playoff spot or a club with an eye on next year, each organization has the chance to expand its roster by two spots.

In choosing one prospect for every team who could make an impact in September, we tried to look at players who are ready and might be given an opportunity, given the needs of the big league team. Prospects already on the 40-man roster might have a leg up, though that’s not an obstacle for all teams. And many of the selections -- 12 to be exact -- have already gotten a taste of the big league life this season.

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AMERICAN LEAGUE EAST

Blue Jays: Jake Bloss, RHP (No. 3)
Bloss made three Major League starts with the Astros before his Deadline move to the Jays in the Yusei Kikuchi trade, but that was out of injury necessity. Toronto has played it slower with the breakout righty, first sending him to work in its pitching lab in Dunedin, Fla., and then to Triple-A Buffalo to find his footing. His fastball-curve-slider mix doesn’t need a ton more refinement, and he could get a few looks up north to solidify his standing in the 2025 rotation heading into the offseason.

Orioles: Coby Mayo, 3B/1B (No. 2/MLB No. 10)
Mayo's first taste of the big leagues didn’t go as planned (1-for-17, 10 K), but that’s only going to help him be prepared for the next time the phone rings. Just 22, he’s going to get to that power in Baltimore soon enough. He played third with Jordan Westburg on the IL the first time; maybe he gets ABs at both infield corners, and even DH, to provide an offensive boost down the stretch.

Rays: Joe Rock, LHP (No. 23)
If Tampa Bay was more competitive in the postseason race, we’d make a case for the Minors' stolen-base king Chandler Simpson to make a late-season cameo. Alas, he still hasn’t played at Triple-A. Instead, Rock has been with Durham all season long, posting a 4.64 ERA with 102 strikeouts in 110⅔ innings. Acquired from the Rockies in March, the 6-foot-6 southpaw is Rule 5-eligible in the offseason anyway, and the Rays could find a way to use his lower-slot delivery.

Red Sox: Chase Meidroth, INF (No. 11)
Boston just promoted its Big 4 (Marcelo Mayer, Roman Anthony, Kyle Teel, Kristian Campbell) to Triple-A, but Meidroth has been there all season long, slashing .294/.445/.395 with 12 steals in 101 games. The 2022 fourth-rounder out of San Diego is an on-base machine whose best position is second base, which has been a revolving door for the contending Red Sox.

Yankees: Jasson Domínguez, OF (No. 1/MLB No. 17)
Signed for $5.1 million out of the Dominican Republic in 2019, Domínguez lived up to his hype by homering off Justin Verlander in his big league debut and going deep three more times in his next seven games at age 20 last September -- but he blew out his right elbow and required Tommy John surgery. He's healthy again, hitting .314/.378/.487 with seven homers and 10 steals in 41 games between three levels and could be an upgrade over Alex Verdugo.

AMERICAN LEAGUE CENTRAL

Guardians: Chase DeLauter, OF (No. 2/MLB No. 42)
A 2022 first-rounder out of James Madison, DeLauter has endured repeated foot injuries in pro ball but has batted .318/.386/.500 in 91 Minor League games when healthy and tore up the Arizona Fall League last season. He features an impressive combination of size, athleticism, performance and plate discipline that could help the outfielder-needy Guardians hold onto their lead in the AL Central.

Royals: Noah Cameron, LHP (No. 12)
Cameron only just debuted with Triple-A Omaha on July 31, but his results have been too good to ignore. The 25-year-old southpaw has posted a 1.07 ERA and 0.83 WHIP with 30 strikeouts and only four walks in four starts (25⅓ innings). Cameron’s 78-80 mph changeup has been particularly effective with a 51.6 percent whiff rate in Triple-A, and he throws plenty of strikes. With Kansas City jockeying for playoff position, it might turn to its hottest pitcher in the Minors.

Tigers: Ty Madden, RHP (No. 16)
It’s been a rough go at Triple-A Toledo this year for Madden, who has a 7.97 ERA and 1.77 WHIP at the Minors’ top level. However, he has been getting strikeouts of late (37 over his last four starts/24 innings), and he is Rule 5-eligible this offseason, meaning a 40-man decision is looming anyway. The Tigers believe the 2021 32nd overall pick’s 92-95 mph fastball and 82-85 mph slider would at least make him a Major League reliever, and they may want to give him a small taste of The Show before deciding his long-term role.

Twins: Andrew Morris, RHP (No. 9)
It’s almost an art form the way the Twins find pitching talent in later rounds of the Draft, and they’ve already gotten help from David Festa (13th round) and Zebby Matthews (eighth round). Could Morris, a fourth-rounder in 2022, be next? He started the year at High-A and now he’s in Triple-A, leading the organization in ERA (2.16) to go along with a .214 BAA and 1.05 WHIP. The Twins’ staff is deep, but Morris looks ready to assist when called.

White Sox: Colson Montgomery, SS (No. 2/MLB No. 28)
Montgomery is going through the worst season of his four-year pro career, hitting .206/.325/.369 with 13 homers in 101 games at Triple-A Charlotte. But the 2021 first-rounder from an Indiana high school is still just 22 and the best position prospect the White Sox have, and he needs to be added to the 40-man roster in the offseason, so it's worth getting him acclimated to the Majors.

AMERICAN LEAGUE WEST

Angels: Christian Moore, 2B (No. 2/MLB No. 80)
The running joke is that when predicting which recent draftee will get to the big leagues first, just take whoever the Angels select in the first round. Moore certainly is playing into the narrative by jumping to Double-A in a hurry and putting up a .413/.464/.762 line while leading all 2024 draftees in total bases (48) and home runs (six). There is no one in Los Angeles blocking him at second base either.

Astros: A.J. Blubaugh, RHP (No. 9)
The Astros traded Jake Bloss and Will Wagner to the Blue Jays in July and recently promoted Zach Dezenzo and Shay Whitcomb, leaving Blubaugh as their best impact callup candidate. Drafted in 2022's seventh round out of Milwaukee, he has converted from reliever to starter in pro ball and impressed with a four-pitch mix highlighted by a 92-95 mph fastball with ride and run and an 82-85 mph slider. He has logged a 4.20 ERA with 87 strikeouts in 94 1/3 Triple-A innings.

A’s: Jacob Wilson, SS (No. 1/MLB No. 26)
If it hadn’t been for a hamstring injury, Wilson would still be in the big leagues. He’s officially on a rehab assignment in Triple-A and has gone 2-for-8 in his first three games, not surprisingly striking out just once. We all want to see Wilson’s extreme feel for contact and how it works at the highest level for an extended period of time after posting an absurd .430/.469/.668 line in 49 Minor League games this season with a 6.7 percent K rate.

Mariners: Tyler Locklear, 1B (No. 6/MLB No. 93)
Locklear went just 7-for-45 during his first time with the Mariners, though he did homer twice. But there’s confidence in his ability to hit, and with power, over the long haul. He’s slugged .503 with an .896 OPS in his Minor League career since the Mariners took him in the second round of the 2022 Draft and his 16 homers (18 if you count his big league production) this year represent a career high. The M’s offense hasn’t exactly been humming and Locklear could still be seen as a run-producing upgrade at first base.

Rangers: Jack Leiter, RHP (No. 4)
Though Leiter hasn't progressed as rapidly as expected since the Rangers drafted him No. 2 overall out of Vanderbilt in 2021, he's missing more bats this year in Triple-A. He has fashioned a 3.66 ERA with a .219 average-against and 101 strikeouts in 71 1/3 innings. His mid-90s fastball and upper-80s slider are real weapons, and he's ready for another shot at the Majors after getting rocked for a 16.39 ERA in his first three starts there.

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NATIONAL LEAGUE EAST

Braves: Hurston Waldrep, RHP (No. 3)
Waldrep’s big league debut was, to be blunt, awful, and he landed on the injured list with elbow inflammation after his two-start stint. His first few outings on his rehab assignment didn’t exactly instill confidence, but the 2023 first-round pick has given up just one run over his last two starts, spanning nine innings. His last outing was a hitless five-inning affair, though he did walk six. The Braves, clinging to a Wild Card spot, could consider shortening him up for the final month of the season, where his nasty splitter alone could be a big asset out of the bullpen.

Marlins: Deyvison De Los Santos, 1B/3B (No. 5)
Acquired from the Diamondbacks for A.J. Puk in July, De Los Santos has some of the best raw power and exit velocities in the Minors, which he leads in homers (34), total bases (259) and RBIs (101) while slashing .317/.370/.617 between Double-A and Triple-A. The Marlins are tied for 27th in the Majors in homers and should figure out if his pop will play at that level.

Mets: Brandon Sproat, RHP (No. 1/MLB No. 40)
David Stearns has indicated he’d like to see Sproat “dominate” Triple-A before giving him serious MLB consideration. So this may not be a Sept. 1 callup if it does happen, since the righty only has two Syracuse starts under his belt. But the Mets are still chasing that final NL Wild Card spot, and with four above-average pitches (fastball, slider, changeup, cutter), Sproat has the look of one of the best arms in the entire organization. Even if it’s as a limited relief arm to keep his innings in check, the 2023 second-rounder could be a valuable asset at a critical time.

Nationals: Dylan Crews, OF (No. 1/MLB No. 3)
Washington already called up one of its two premier outfield prospects in James Wood last month, and the other is waiting in the (red) wings at Triple-A Rochester in Crews. The 2023 second overall pick’s numbers have been solid in the International League (103 wRC+), but most notably, he’s cut down his strikeout rate by seven points from Double-A with impressive in-zone contact rates and hit for more power, putting up above-average exit velocities. With Wood in left and Jacob Young locked in center, the Nats may want to slide Crews into right to give the group a full look heading into the offseason.

Phillies: Seth Johnson, RHP (No. 15)
This could be an early return on a Trade Deadline investment. The Phillies got Johnson from the Orioles in the Gregory Soto deal and they may have picked up the right-hander at exactly the right time. With Tommy John surgery finally firmly in his rearview, Johnson has been outstanding most of this year, and he tossed five innings of shutout ball in his Triple-A debut in his last start. He’s on the 40-man, so that hurdle is cleared and the back of the Phillies’ rotation is far from solid.

NATIONAL LEAGUE CENTRAL

Brewers: Jacob Misiorowski, RHP (No. 3/MLB No. 66)
Many evaluators across the game have long believed Misiorowski could be a huge weapon out of the bullpen, and lo and behold, once the righty debuted with Triple-A Nashville on Aug. 3, he began pitching in shorter stints. Using his upper-90s fastball, low-90s cutter/slider and mid-80s curveball, Milwaukee’s top pitching prospect has tossed four straight scoreless (and walkless) appearances for the Sounds, totaling 7⅔ innings. With the Crew in the midst of a potentially special season, Misiorowski’s dynamic stuff might be too good to leave in the Minors.

Cardinals: Michael McGreevy, RHP (No. 11)
The 2021 first-rounder made a spot start in his MLB debut on July 31 and passed that test, giving up only one earned run over seven innings against the defending World Series-champion Rangers. If and when St. Louis has another rotation opening in September, it shouldn’t shy away from turning back to McGreevy, who showed six different pitch types in that first outing and has a long history of throwing strikes.

Cubs: Owen Caissie, OF (No. 3/MLB No. 36)
The Cubs have six Top 100 prospects in Triple-A and the most likely to get the call to Chicago is Caissie, who was part of the Yu Darvish trade with the Padres in December 2020. One of the best power-hitting prospects in the Minors, he's batting .268/.368/.443 with 13 homers in 101 games and just turned 22 last month.

Pirates: Nick Yorke, 2B/OF (No. 6)
Acquired from the Red Sox at the Trade Deadline for Quinn Priester, Yorke is having the best year of his career since his 2021 debut season after Boston made him a surprise first-round pick. He’s made a very strong first impression with his new organization, hitting .359/.408/.861 over his first Triple-A games. He’s played second and all three outfield spots to give many options of how to get his bat into the lineup. The Pirates offense needs help and Yorke needs to be added to the 40-man this offseason anyway, so why not see what he can do as a precursor to 2025?

Reds: Rhett Lowder, RHP (No. 2/MLB No. 35)
This one is more wishful thinking than realistic possibility, though we all thought Lowder could have been one of those college pitching draftees to make it to the big leagues in his first full season. He hit some bumps in Double-A but has apparently figured things out over his last six starts. The right-hander has posted a 1.06 ERA, .172 BAA and a 0.794 WHIP over 34 IP in that span and it sure would be exciting to see the Reds reward that turnaround with a taste of the big leagues to get him ready for next year.

NATIONAL LEAGUE WEST

D-backs: Yilber Diaz, RHP (No. 6)
The 24-year-old right-hander has been one of the breakout prospects in the Arizona system this summer and already made four MLB starts in July, not giving up more than one earned run in three of them. His breaking stuff (low-80s slider, upper-70s curve) was particularly impressive at generating whiffs, and the heat on his 95-97 mph is clearly ready for the bright lights. He’s already at a career high for innings (106⅓), but his arsenal could play in the bullpen should Arizona choose that route too.

Dodgers: Justin Wrobleski, LHP (No. 6)
The Dodgers seem to have an endless string of pitching injuries and a limitless supply of mound prospects to fill those holes. An 11th-rounder from Oklahoma State in 2021 -- two months after having Tommy John surgery -- Wrobleski is a four-pitch lefty with a lively 93-96 mph fastball, impressive feel for spin and lots of strikes. He has compiled a 3.57 ERA with an 89/26 K/BB ratio in 88 1/3 innings between Double-A and Triple-A and posted a 4.68 ERA in five starts for Los Angeles.

Giants: Mason Black, RHP (No. 9)
The highest-drafted pitcher ever from Lehigh (third round, 2021), Black relies heavily on a 92-94 mph sinker and a sweeping 82-85 mph slider. He got off to a hot start in Triple-A this year before getting hammered for an 8.79 ERA with San Francisco in May, then struggled after his demotion until he got on a roll in August. He has a 2.91 ERA in four starts this month with an overall mark of 4.59 with 87 strikeouts in 84 1/3 Triple-A innings.

Padres: Alek Jacob, RHP (No. 16)
San Diego’s Deadline bullpen additions squeezed Jacob out of an MLB spot for now, but September offers a new opportunity for the funky righty with elite extension. Jacob struck out 13 of the 25 batters he faced during his most recent four-game MLB run, and his changeup, four-seamer and sweeper all posted whiff rates above 50 percent. It isn’t a typical arsenal for the modern game -- nothing averages above 88 mph -- but with a postseason run upcoming, the Padres should turn to what’s clearly been effective in small samples so far.

Rockies: Yanquiel Fernandez, OF (No. 5/MLB No. 96)
The Rockies are playing for the future and they’ve already called up catcher Drew Romo to give him a chance to show what he can do. Fernandez hasn’t set the world on fire since he got bumped up to Triple-A, but he’s been swinging it better of late. He’s on the roster and has the chance to be a big part of the turnaround in Colorado, so the club should give him a head start now.