Toolshed: September call-up preview

The Toolshed focuses on some of the more interesting prospect-centered storylines of the 2015 season. Have ideas, feedback or questions for Sam? Email him or tweet him @SamDykstraMiLB. (Note: All stats are through Wednesday's games.)

September will bring the end of the Minor League season, but for many prospects, it'll also bring the thing they've coveted since they first picked up a bat and ball -- a promotion to the Major Leagues.

On Sept. 1, Major League clubs are allowed to expand their rosters to include any players on their respective 40-man rosters. For some prospects, that means a return to the Majors after a cup of coffee or two earlier in the season. For others, it means that first taste of Major League action at a crucial time down the stretch toward the postseason. 

Here are players ranked among MLB.com's top 100 prospects who are already in the Majors, will most likely join the big leagues in September, are question marks for a call-up or for whom you shouldn't get too excited to see in a big league park near you anytime soon.

Already up

Byron Buxton (Twins), Trea Turner (Nationals), Luis Severino (Yankees), Michael Conforto (Mets), Aaron Nola (Phillies), Jon Gray (Rockies), Henry Owens (Red Sox), Ketel Marte (Mariners), Stephen Piscotty (Cardinals)

More than likely

Joey Gallo, 3B/OF, Rangers: If you can, ignore the .188 average and 39.4 strikeout percentage at Triple-A for a second. Gallo still has tremendous power, as evidenced by his .258 ISO in the Pacific Coast League and his 27 homers across all levels, including five over 25 games in the Majors this season. As of Wednesday, the Rangers sit just half a game behind the Twins in the Wild Card race, and with Gallo on the 40-man roster, they can't let that opportunity to use his left-handed thump off the bench pass them by.

Steven Matz, LHP, Mets: We'll be the first to admit this is a little bit of a cheat. Matz is currently on the Major League disabled list after tearing a left lat muscle in his second start with the Mets on July 5. He's made three rehab appearances already in the Minors and is expected to make one more start before returning to the big leagues. The NL East-leading Mets will likely move to a six-man rotation for the stretch run once Matz, who gave up just two earned runs in 13 innings over his first two MLB starts, comes back.

Jose Peraza, 2B, Dodgers: Peraza makes this 3-for-3 in terms of players who already made their Major League debuts this summer and are likely to return come September. Peraza joined the Dodgers as part of the massive three-way trade among the Dodgers, Braves and Marlins and played a pair of games for the big club two weeks ago during a brief promotion. The 21-year-old second baseman, who has experience in the outfield, has 75-grade speed that would be a big help for the Dodgers off the bench as they try to hold onto their NL West lead. The only thing that could delay Peraza's return to the Majors is if the parent club decides they'd rather let him play regularly during Triple-A Oklahoma City's own postseason run. In any event, expect Peraza up, if not by Sept. 1 then at some point during the month.

Archie Bradley, RHP, D-backs: It's been a bit of a down year again for the D-backs' No. 2 prospect, who is 2-3 with a 5.80 ERA in the Majors this season. Right shoulder inflammation has kept him out of the Major League rotation since June 1, and the D-backs optioned him to Triple-A Reno after his second rehab start last Sunday. The organization wants its top pitching prospect to get results there before the Minor League season is over, but considering he's on the 40-man roster, he'll still have a chance to add innings in the Majors in September.

Dalton Pompey, OF, Blue Jays: Pompey's organizational trajectory this season is likely to resemble a parabola. He started in the Majors but was sent down to Triple-A in May after hitting just .193 in the first month. The 22-year-old switch-hitter fell as far as Double-A New Hampshire before bouncing back to Buffalo in mid-July. He's hit .333 with a .424 OBP in 37 games since returning to Triple-A and looks primed for a second straight September promotion. Pompey won't unseat defensive wizard/breakout star Kevin Pillar in center, but the Jays will welcome his improved bat and plus defense off the bench.

Frankie Montas, RHP, White Sox: It's coming two months later than it could have, but Montas will likely finally make his Major League debut in September. The White Sox brought up their No. 3 prospect back in July as the 26th man/emergency arm in a doubleheader but did not end up using him. The 22-year-old was added to the organization's 40-man roster last November and has posted a 2.27 ERA with 108 strikeouts in a career-high 112 innings at Double-A Birmingham this summer. Chicago could limit his innings by putting him in the bullpen, and if they do, watch out: Montas hit 101 mph on the gun during his relief outing in this year's Futures Game.

Carl Edwards Jr., RHP, Cubs: Speaking of Windy City relievers, MLB.com's No. 62 overall prospect will likely get the call to the Majors after spending his first season in the bullpens of Double-A Tennessee and Triple-A Iowa. Edwards, who had to be added to the Cubs' 40-man in the offseason, has been almost unhittable, holding opposing batters to a .139 average while fanning 73 in 53 1/3 innings but has struggled some with control by averaging 6.9 walks per nine innings. Still, the Cubs won't shy away from letting him show off his electric stuff in their march to their first postseason since 2008.

Alen Hanson, 2B, Pirates: Hanson isn't exactly banging down the door to the Majors, but as a player on the Bucs' 40-man roster, he has to be considered a tool in their bag. The 22-year-old has hit .265 with a .709 OPS over 108 games in his first season at Triple-A Indianapolis. His speed, easily his best tool, has manifested itself in the form of 11 triples and 31 stolen bases. As with Peraza, the Pirates might decide they'd rather let Hanson get playing time in the playoffs with Indianapolis, but there's no doubt they'd like his speed off the bench when they can get it. 

Jorge Polanco, SS, Twins: The Twins haven't been shy about using young talent this season, and it's paid off since they are a surprise Wild Card contender. They've even called up Polanco twice already this season, and he's gone 3-for-10 (.300) in four games, three of which were starts. The 22-year-old shortstop, who has a .289/.341/.392 line between Triple-A Rochester and Double-A New Britain, doesn't have one standout tool, but given that Twins shortstops rank 27th in the Majors with a -0.2 fWAR, Minnesota will take all the reinforcements it can get at the position.

Could get a look

Corey Seager, SS, LA Dodgers: Every prospecthead (and maybe his or her cousin) would love to see this happen. Seager is the game's top prospect still in the Minors and has handled himself well as a 21-year-old at Double-A and Triple-A with a .292/.342/.481 line and 17 homers at the two levels. Throw that together with Jimmy Rollins' ineffectiveness at shortstop, and you'd think that'd be good enough to earn him a Major League roster spot. But there are roadblocks, namely Seager's absence from the 40-man roster. The Dodgers would have to clear a spot there before bringing up the left-handed slugger, and given that he's not Rule 5 eligible until 2016, they might not be in a rush to make that happen. It could depend on how safe they feel in their ability to hold off the Giants in the NL West.

Jose Berrios, RHP, Twins: Berrios is another prospect not currently on the 40-man roster, but would be great to see cut his teeth against Major League competition. The righty has been excellent lately at Triple-A Rochester, positing a 2.12 ERA with 43 strikeouts and three walks in 34 innings this month. He's got a Major League fastball right now, something that Twins general manager Terry Ryan saw first-hand during Berrios' 12-K performance Wednesday. One possible hitch beyond the 40-man add: The 21-year-old right-hander is already at a career-high 155 1/3 innings, so the Twins might not want to push him very far beyond that.

Robert Stephenson, RHP, Reds: Reds manager Bryan Price was refreshingly frank in the way he discussed a potential call-up of his club's top pitching prospect, saying, "There's a chance [Stephenson] could be part of that September conversation." As Price noted, Stephenson has a few innings left in him after being sidelined with a strained right wrist for two weeks in August and could make up for that missed time with the Reds, who are in a position to give their young talent chances without the pressure of a playoff race. Stephenson had a 2.77 ERA with 26 strikeouts in five starts (26 innings) before the injury.

Mark Appel, RHP, Astros: Put this one down as "fairly unlikely" but a move we won't immediately rule out. Appel, who isn't on Houston's 40-man roster, has been under Astros fans' collective microscope since he was taken first overall in 2013. Scouts still love his stuff -- his fastball, slider and changeup were all given plus to plus-plus grades by MLB.com -- but the results haven't been consistent as he's put up a 4.46 ERA between Double-A and Triple-A. All that said, the Astros, who lead the AL West by 5 1/2 games, have a chance to really go for it and might want as much top talent in the Majors as they can get.

Blake Snell, LHP, Rays: If any pitcher has earned a long Major League look this season, it's Snell. The 22-year-old left-hander is a candidate for Breakout Prospect of the Year (an award won by Daniel Norris last year), thanks to his 1.31 ERA, 0.98 WHIP and 151 strikeouts in 124 innings across three levels. He hasn't allowed more than one earned run in any of his seven Triple-A starts, but that stat does come with a caveat. The Rays have limited him to around five innings per start since he made the jump to Triple-A to keep him healthy in the final month of the Minor League season. They'll likely shy away from adding innings on top of that in the Majors, but there is a possibility that the strategy was put in place so that Snell could squeeze in a few more frames come September.

Don't hold your breath

(Note: To save us all time, this is the disclaimer that none of the following players is on his respective organization's 40-man roster.)

Aaron Judge, OF, Yankees: The lack of a 40-man spot didn't keep the Yankees from adding Greg Bird or Luis Severino in August, and there was a chance it wasn't going to stop them from adding Judge in September. Was a chance. That is, until Yankees general manager Brian Cashman told NJ Advance Media on Thursday in no uncertain terms that Judge won't make his MLB debut next month. Judge has a .232/.319/.405 line with eight homers in 49 games since getting bumped up to Triple-A, so perhaps it's for the best. But it's tough to say that a struggling Yankees offense couldn't have used the 2013 first-rounder's power in some way this season.

Tyler Glasnow, RHP/Josh Bell, 1B, Pirates: We'll group these two close friends together because it's equally unlikely that either will join the Bucs in September. The Pirates don't have a history of bringing up their top pitching prospects, like Gerrit Cole and Jameson Taillon, in recent years. So though you may be mesmerized by Glasnow's 0.99 ERA and 34 strikeouts in 27 1/3 Triple-A innings, just know it's more likely he's going to make up the innings he missed due to an ankle injury in the Arizona Fall League. As for Bell, his .333/.412/.524 Triple-A line might suggest he's ready to make the jump. But the 23-game sample isn't big enough to be making any grand assumptions, and the Pirates probably would rather see him continue to get playing time in the International League playoffs while Pedro Alvarez continues to heat up as the Major League first baseman.

Julio Urias, LHP, Dodgers: A 19-year-old in the Majors! How fun would that be? And a nasty 19-year-old at that. Urias pitching in the Majors would be quite the sight, especially to see how big league hitters would handle his fastball-curveball-changeup mix. Plus, Urias has tossed only 76 innings this season after missing time due to cosmetic eye surgery. We could keep going on and on about what a thrill it would be to see Urias, but it's not happening. The Dodgers will take his 2015 as yet another stepping stone toward a promising big league career and leave it at that.