Oh September , and here are the call up's

MLB rosters will expand up to 40 on September 1. Are there any September callups who should be on the fantasy radar? Yet-to-be promoted prospects who might get a real shot at playing time over the final month of the regular season? After-the-hype guys getting a second shot? Speed threats? Spot starters?

Pirates right-hander Tyler Glasnow used up his prospect eligibility earlier this year, but I’m as excited to see him get another chance as I am about any other likely September callup (assuming the Braves’ Ronald Acuna doesn’t get the call). Glasnow has been on a ridiculous run since getting demoted to Triple-A Indianapolis, amassing a 2.06 ERA and a 131/31 K/BB ratio in 87 1/3 innings. Most encouraging is that he wasn’t walked more than two batters in any of his last six starts. Control has always been his biggest problem (he walked 62 in 110 2/3 innings in Triple-A last year), and if this step forward carries over, he could be a stud this time around. Most likely, he would have been promoted earlier this month, except the Pirates have been able to push back his free agency by a year by keeping him down.

The Athletics need to figure out if 23-year-old Renato Nunez should fit into their 2018 plans after a 2017 season in which he’s hit .253/.314/.529 with 32 homers in 450 at-bats for Triple-A Nashville. They’re hopeful that they’re set at the infield corners for the next several years with Matt Olson at first and Matt Chapman at third, but Olson isn’t a sure thing and designated hitter Ryon Healy also looks vulnerable, what with his .758 OPS this year and complete lack of defensive value. Nunez, primarily a third baseman in his minor league career, will probably play some left field and spend some time at DH next month. I don’t necessarily think he’ll be a mixed-league guy, but he could have a little run like Olson did this month.

Cardinals pitching prospect Jack Flaherty was a first-round pick out of Harvard Westlake High School in California in 2014, and while he doesn't have the same kind of stuff as some of the organization’s higher-ranked arms, he might be the safer prospect because of his ability to locate. It's not like the arsenal is poor, either; he throws a low-90s fastball, and he shows the same exact arm speed on a changeup that flashes 65-70 grades. He also shows an above-average slider, and occasionally a usable curve. He repeats his delivery well, and the command projects at least above-average. Don't expect a ton of strikeouts, but he'll keep the ball in the park, and assuming he throws strikes at the same rate he should have success early on. His ability to provide fantasy production down the stretch will of course depend on his role. St. Louis may use Flaherty out of the bullpen at first.

A few months ago, Phillies shortstop prospect J.P. Crawford wouldn't even be worth mention, as he was hitting below .200 for the a large portion of the season. Since July, however, Crawford has a .925 OPS, and he's made more hard contact while still maintaining a quality approach at the plate. At one point this was one of -- if not the -- best prospects in baseball, and he's played like it for most of the second half of the season. He won't provide much value on the bases, but he should hit/get on-base enough to be a starter at a premium position going forward.

I’ve got my eye on another Phillies prospect: Scott Kingery. It’s not a sure thing that he will be called up next month, but there is growing chatter that he might and the 23-year-old has played all the right notes this season in the upper minors to force that move. As of Tuesday afternoon, Kingery is slashing .306/.359/.543 with 26 home runs and 28 stolen bases in 125 games between Double-A Reading and Triple-A Lehigh Valley. He was drafted as a second baseman and that is the position he has played primarily in 2017, but Kingery has also been taking grounders at shortstop and third base as Philadelphia’s brass sorts out a long-term spot for him at the big league level. If he gets the call and the playing time is there, the former second-round pick has the goods to provide an immediate mixed-league impact.

As for potential spot starters, how about Twins pitching prospect Stephen Gonsalves? The 24-year-old southpaw boasts a 2.96 ERA, 1.09 WHIP, and 118/29 K/BB ratio in 109 1/3 innings this season between Double-A Chattanooga and Triple-A Rochester, and his rate stats were even better last season. Minnesota currently holds the second AL Wild Card spot and Gonsalves could immediately provide the club a significant rotation upgrade as that race heats up. In the right matchups, he could be playable in mixed fantasy formats.

  I'm not totally convinced that Brent Honeywell will be added to the Rays' rotation in September, especially after he was just suspended for four games at Triple-A Durham for disciplinary reasons. The club could just turn to Matt Andriese if they make a rotation change, and they might get Jacob Faria (abdomen) back eventually. However, Honeywell needs to be added to the 40-man roster to be protected from this winter's Rule 5 Draft, and workload shouldn't be an issue for him since his 131 1/3 innings this year are just 15 more than he had in 2016 and one more than he had in 2015. The 22-year-old has posted a 3.63 ERA and 167/35 K/BB ratio between two Double-A and 23 Triple-A starts this season. Honeywell is arguably the top pitching prospect in the game and can be mixed-league relevant immediately if he gets a shot.

Jeimer Candelario is off to a rotten .255/.286/.434 start at Triple-A Toledo since the Cubs traded him to the Tigers in the Justin Wilson deal, but Detroit will give him a look in September anyway. The hope, undoubtedly, is that he'll show well in the final month so that the Tigers feel comfortable with him as their third baseman going into 2018 and they can move Nicholas Castellanos to the outfield. Candelario's numbers in the minors don't jump off the page. He doesn't run at all and his season high in home runs is this year's 15 (16 if you count the one he hit for the Cubs). That said, aside from a rocky start with Toledo he has consistently shown excellent plate discipline, which is especially impressive considering he's always been well younger than most of the guys he's playing against. Candelario might be more of an AL-only guy for 2018, but he should be on your radar.