Toolshed: September callup preview

That time of year is almost upon us again -- the time of the season when the Majors get filled with many of the fresh faces we've come to know in the Minors over the last five months.

On Sept. 1 each season -- in this case, next Thursday -- active Major League rosters are able to expand to include any and all members of an organization's 40-man roster. That doesn't mean 40 players have to be in every Major League clubhouse, nor do all 40-man members have to be with the club on the first of the month. In short, all September roster expansions are not made equal. Clubs can choose not to promote 40-man members or postpone bringing them up for any number of reasons -- perhaps to let them complete their Minor League regular season or compete in the postseason.

So some of the names you'll see below might join their clubs Thursday, others much later. (Remember the Royals didn't bring up Raul Mondesi until Oct. 27, right before the World Series.) So with that, here are some of MLB.com's top 100 overall prospects that are already in the Majors, can expect a call next month, have a somewhat decent chance at a promotion or aren't at all likely to make the jump to the game's highest level.

Already up

Alex Bregman (Astros), Dansby Swanson (Braves), Andrew Benintendi (Red Sox), Alex Reyes (Cardinals), Orlando Arcia (Brewers), David Dahl (Rockies), Josh Bell (Pirates), Aaron Judge (Yankees), Gary Sanchez (Yankees), Jeff Hoffman (Rockies), Raul Mondesi (Royals), Jake Thompson (Phillies), Braden Shipley (D-backs), Joe Musgrove (Astros), Luke Weaver (Cardinals), Mike Clevinger (Indians)

If that feels like a lot, that's because it is. Even last season -- the so-called Year of the Prospect -- only eight of MLB.com's top 100 prospects were already in the Majors at the time of our September preview. That number's jumped to 16 this time around (it was 18 until Jose Berrios and Reynaldo Lopez were optioned Thursday, though they'll likely be back in September), meaning almost one in six of the game's top prospects is already playing at the top level. Is there some link here between last year's success among rookies and organizations trusting their young players more this time around? Perhaps. But that's a discussion for another day. We're here to figure out that age-old prospect question. Who's next?

More than likely

Joey Gallo, 3B/1B/OF, Rangers: For the second straight season, MLB.com's No. 12 prospect leads the group of likely prospects to make the jump, and it should take less convincing this time around. The 22-year-old slugger has made solid improvements in his return to Triple-A Round Rock with a .251/.382/.570 line and 25 homers over 91 games in the Pacific Coast League. He's still striking out plenty at 33.6 percent, but he's bringing ample power as always with a .319 ISO that ranks second in the Minors behind only Dylan Cozens (.324). Gallo has already been called up to Texas twice this season but played sparingly until going 0-for-9 with seven strikeouts in three straight starts at DH from July 28-30 before being returned to Triple-A. His bat remains far too good to ignore, though, and the AL West-leading Rangers can be expected to bring him back the first day of September as they did in 2015. Gallo has played first and third base almost equally this season with some left field sprinkled in as well. Texas might want to get some looks at first, though, with Mitch Moreland approaching free agency this winter.

Lucas Giolito, RHP, Nationals: There's a decent chance Giolito will be up with the big club Sunday, four days before rosters expand. The Nats had their top prospect go only one inning Tuesday to preserve him as a starting option given injuries to Joe Ross and Stephen Strasburg and some ineffectiveness from Reynaldo Lopez. But even if he isn't up by the weekend, Giolito can definitely expect a call at some point in September because of his stellar stuff (notably a deadly fastball-curveball combo) and the fact that he's settled in nicely at Triple-A Syracuse, where he owns a 2.76 ERA with 35 strikeouts in 29 1/3 innings. Giolito's arm is one the NL East leaders could use in any capacity, and with three so-so Major League appearances under his belt, the right-hander could use a few more chances to show Washington he's ready for a full-time role in 2017.

Manuel Margot/Hunter Renfroe, OF, Padres: This is a pretty simple one, considering Padres general manager A.J. Preller told reporters last month that San Diego would do a "more traditional Septemer call-up" for the organization's top two position player prospects. Even then, those calls might be delayed with Triple-A El Paso looking like a good bet to head to the PCL playoffs. The cellar-dwelling Padres can afford to wait to see which of Margot or Renfroe profiles well with current outfield mainstays Travis Jankowski and Alex Dickerson. Margot, who has a .302 average in his first Triple-A season, is by far the better fielder and could give Jankowski a run for his money in center. But Renfroe has the more advanced bat with a .910 OPS and 25 homers this season and has the arm to fit in right, where the Padres have played Jabari Blash, Christian Bethancourt, Patrick Kivlehan and even Wil Myers this month alone. Both Margot and Renfroe should get plenty of chances to prove themselves in the season's final month.

Tyler Glasnow, RHP, Pirates: This is another gimme, but we'll take it. The Pirates' top prospect made his second start with the Pirates on July 23 but has been on the disabled list ever since due to right shoulder discomfort. He's made two rehab appearances with Double-A Altoona and is scheduled to start Saturday for Triple-A Indianapolis. When healthy, Glasnow has been his usual dominant yet walk-heavy self with a 1.94 ERA, 122 strikeouts and 55 walks in 102 innings at Triple-A this season. He allowed five earned runs on seven hits in 8 1/3 innings with the big club before the injury but should be given every chance to show that he can help lead a Pittsburgh rotation alongside Gerrit Cole and Jameson Taillon starting next month.

Carson Fulmer, RHP, White Sox/Robert Stephenson, RHP, Reds: These final two picks aren't as sexy as the ones above, but they are top-100 prospects likely headed to the bigs in September. Both Fulmer and Stephenson have pitched in the Majors this season already without much success. What's more, neither Fulmer (5.18 ERA, 94 K, 54 BB in 92 IP) nor Stephenson (4.66 ERA, 106 K, 65 BB in 123 2/3 IP) have done enough in the Minors in 2016 to bang down the door. But both have the stuff to succeed, already take up spots on the 40-man and play for organizations with nothing to lose in September. They should get the ball with lots to prove.

There's a chance

Jose De Leon, RHP, Dodgers: Everything in our bones made us want to put De Leon in the category above, since it makes too much sense for Los Angeles to bring up its No. 2 prospect sooner rather than later. First, there is all starting pitching injuries -- when both Brett Anderson and Scott Kazmir hit the disabled list this week, Los Angeles tied a Major League record with 27 different players on the DL this season. But that alone is not why De Leon deserves a shot. The 24-year-old right-hander has also been awfully good lately with a 1.59 ERA, 33 strikeouts and only four walks in his last five starts (34 innings) for Triple-A Oklahoma City. Add in that he's thrown only 78 2/3 innings due to injuries earlier in the summer, and there's plenty left in the tank for MLB.com's No. 38 prospect, who has a plus fastball and changeup to go with an improving breaking ball. De Leon isn't on the 40-man yet, but he's Rule 5 eligible this offseason, so the move would be coming soon. If the Dodgers are going to hold off the Giants, they need their best healthy arms in the Majors, and De Leon ticks both boxes.

Yoan Moncada, 2B/3B, Red Sox: Moncada is the highest-ranked prospect left in the Minors and has impressed in all facets in his second full stateside season. The 21-year-old switch-hitter hasn't come across any speed bumps since making the jump to Double-A Portland, where he owns a .285/.386/.563 line with 10 homers and eight steals in 39 games. Normally a second baseman, the Cuba native has played his last four games at third base, which just so happens to be where the Red Sox could use help given the struggles of Aaron Hill and Travis Shaw. Even if Moncada weren't playing everyday for Boston, he could provide the club with a big boost off the bench as a pinch-run specialist with his plus speed, though the Sox wouldn't bring him up just for that. The question comes down to whether the Sox want to push their prized prospect quickly, as they did with Andrew Benintendi, or if they'd rather see Moncada develop a little longer with an eye on 2017.

Bradley Zimmer, OF, Indians: With the second-most wins in the American League entering Thursday, the Indians have a solid shot at capturing their first AL Central title since 2007, and they've reached that point without a solid situation in the outfield. In the last week alone, Rajai Davis, Tyler Naquin, Brandon Guyer, Lonnie Chisenhall and Abraham Almonte have received at least two starts in the outfield. Meanwhile, the organization's top prospect, who happens to be a pretty good center fielder, sits one level away at Triple-A Columbus, where he is hitting .292/.388/.348 with five steals in 26 games. While it would seem that Zimmer has the potential to provide a calming influence on a static outfield, things get complicated when you consider Zimmer isn't on the 40-man, won't bump up against Rule 5 eligibility this offseason and would be headed to the International League playoffs if kept in Columbus. It might take an emergency for the Tribe to rush the 23-year-old, but he has the talent to make it work if and when the call comes.

Josh Hader, LHP, Brewers: Here begins a subsection of "Let's see what we have" call-ups among rebuilding organizations. Hader has become the Brewers' top pitching prospect in his first full season with the organization, racking up strikeouts in bunches (154 in 119 innings, second-most in the Minors) and being absolutely devastating against fellow left-handers. Yes, he's put up a 4.79 ERA in 62 Triple-A innings, but that has a lot to do with playing in the hitter havens of the Pacific Coast League in general and Colorado Springs specifically. What's more, the 22-year-old has tossed quality starts in four of his last six outings with the Sky Sox. He even struck out 12 and allowed only two hits over six scoreless frames last time out. Hader's name has already come up in promotion discussion in Milwaukee, and with him being eligible for this year's Rule 5 Draft, it'd make sense to give him a 40-man spot a little early and see how he handles his first taste of the Majors with the Brewers far out of contention.

Lewis Brinson, OF, Brewers: Brinson was a serious candidate for the "Don't hold your breath" section below. He only has 23 games of Triple-A experience between the Rangers and Brewers systems, he's coming off an eight-day DL stint due to a hamstring injury and he's not on the 40-man roster, though he is Rule 5 eligible. With the Brewers in rebuild mode, there's an argument that they don't need to rush their big acquisition from the Jonathan Lucroy deal and should let him get comfortable with the organization in his first offseason. Yet Brinson may well be hitting his way into the September conversation. After homering twice Thursday night, MLB.com's No. 18 overall prospect is 24-for-58 (.414) with four long balls, five doubles, 17 RBIs and four steals in 15 games since joining Colorado Springs. The 22-year-old is capable of providing plenty of value with his bat, his legs and his glove in center, and if he's performing this well now, the Brewers, who have played Kirk Niewenhuis and Keon Broxton in center field, might decide to give Brinson his first shot now while he's hot and confident. Stay tuned.

Amir Garrett, LHP/Jesse Winker, OF, Reds: Like their NL Central brethren in Milwaukee, the Reds don't have much to play for down the stretch and have a couple top-100 prospects who could be ready for their first taste of Major League action. Garrett has been on the 40-man since November 2014 and has been solid at Triple-A with a 3.36 ERA and 43 strikeouts in 56 1/3 innings. He was passed over for a look last year, and rightfully so after pitching the entire season at Class A Advanced, but now might be the time to put that roster spot to good use, even if it's out of the bullpen at first. Winker is a less likely option as a non-40-man outfielder who is blocked by All-Star slugger Adam Duvall in left field. But the 23-year-old is up for the Rule 5 Draft this offseason and hitting .295 with a .759 OPS in the International League (and .325/.815 in August), even though his power has not been there with three homers in 94 games. It's likely that Winker finishes things out in Louisville, but if the Reds want him to get his feet wet, he could make sense as a September rotation option.

J.P. Crawford, SS/Nick Williams, OF, Phillies: Along with catcher Jorge Alfaro -- who's reportedly getting called up today -- Crawford and Williams represent key pieces in Philadelphia's future. Though their chances for a callup this year may be slim, Williams and Crawford are both at Triple-A Lehigh Valley and the former is Rule 5 eligible, though he hasn't exactly banged down the door with a .268/.296/.438 line. Crawford is advanced defensively at short but is a year away from having to be added to the 40-man and might need some more offensive fine-tuning given his .253 average and .669 OPS with the IronPigs. Then again, the Phillies could do what the Braves did with Swanson and bring up their future shortstop now rather than wait.

Don't hold your breath

Clint Frazier, OF, Yankees: There are obviously any number of prospects whom fans might hope in their biggest dreams to see in September but obviously won't, but we'll just focus on Frazier here. The Yankees' top prospect has the same amount of Triple-A experience as Zimmer. He's a new face in town like Brinson. So why is he not even an option? Well for one, Yankees general manager Brian Cashman said so himself. But Frazier also hasn't quite found his footing yet at Triple-A Scranton/Wilkes-Barre, where he is hitting .235 with a .662 OPS through 21 games. He's also a year from Rule 5 eligibility, so the Yanks aren't against this November's deadline to put the 21-year-old on the 40-man. Let him force the issue in 2017.