Bundy, Hamilton among possible call-ups who could impact races

September is usually baseball's showcase month, with top prospects earning their first cups of coffee in the big leagues. This season, however, many of the game's most promising youngsters are already in the majors.

That group is headlined, of course, by the Angels' Mike Trout and the Nationals' Bryce Harper, who were recently joined in the big leagues by third basemen Manny Machado with the Orioles and Mike Olt with the Rangers, outfielder Starling Marte with the Pirates, righthanded starter Matt Harvey of the Mets and lefthanded starter Tyler Skaggs with the Diamondbacks. Similarly, Athletics righthander Dan Straily already had one big league stint and will likely be back up in a few days.

How many more blue chippers will not only get the call but also be in a position to help his club in a playoff chase?

It may not be many. All teams will be summoning a few September call-ups, though mostly it'll be for depth: a third catcher, an extra reliever or two and maybe some situational position player help, such as a lefthanded pinch-hitter, a speedster to pinch-run or a defensive replacement at a position that needs it. To be called up in September, a player needs to be on the 40-man roster.

So here is a list of players on the farms of big league contenders whom the baseball world has been dying to see and what to expect, if anything, from them next month.

Note: All prospect ranks are from Baseball America's Midseason Top 50 Prospects List.

Trevor Bauer, Diamondbacks, RHP

Arizona's trades of shortstop Stephen Drew and starter Joe Saunders didn't fully signal that the club was waving the white flag but at 7½ games out of the wild card (and 8½ out in the NL West), it'll take a big comeback to return to the postseason for the second straight year. If that's to happen, the Diamondbacks will need strong, consistent starting pitching and will look to Patrick Corbin, 23; Skaggs, 21; and, quite likely, Bauer, 21. Last year's first-round pick struggled in four big league starts in July, when he was hampered by a groin injury, but has a 2.78 ERA in five starts back at Triple A.

Dylan Bundy, Orioles, RHP

Baseball's top prospect didn't allow an earned run in 30 innings of Low A ball, then had a 2.84 ERA in 12 starts in High A and on Tuesday night made his third start in Double A, allowing two earned runs while pitching between 5 1/3 and 6 innings in each outing. Bundy is only 19 years old but has been dominant at every stop thus far, and general manager Dan Duquette has already been aggressive in handing third base to the 20-year-old Machado. Look for Bundy to get a shot in the Orioles' bullpen, with the Baltimore Sun touting, "It's now to the point where it would be a surprise if Bundy, who is on the 40-man roster, wasn't [brought up] to experience the Orioles' potential pennant chase."

Nick Castellanos, Tigers, 3B

The natural third baseman and No. 12 prospect has been learning rightfield in Double A after he batted .405 with a 1.014 OPS in 55 games of High Class A ball. His overall offensive numbers have lagged in Double A (.277 average, .717 OPS), but Castellanos has crushed lefthanded pitching (.400 average, 1.043 OPS in 65 at bats). Playing a corner outfield spot and platooning against lefties is an intriguing option for Detroit, but the 20-year-old is not on the 40-man roster and only has 296 Double A at-bats, meaning he is probably a longshot to get the call.

Billy Hamilton, Reds, SS

Pro baseball's all-time single-season leader in stolen bases -- he has 154 in 127 games split between High Class A and Double A -- has more than one trick. Hamilton has batted .310 with a superb .429 on-base percentage in his 45 Double A games to go along with his legendary speed exploits. With fewer than 200 career plate appearances in Double A and none in Triple A, it'd be a stretch to think he'd be a productive everyday player in the majors, even with Zack Cozart's middling .690 OPS. But for a likely playoff-bound team, Hamilton (BA's No. 27 prospect) would seem like a perfect candidate to get a September tryout at least as a pinch-runner even though he's not on the 40-man roster. "It's been discussed," Reds manager Dusty Baker told the Cincinnati Enquirer.

John Lannan, Nationals, LHP

Lannan spent four years in Washington's big league rotation before offseason acquisitions relegated him to Triple A in 2012. He hasn't pitched well in the minors (4.58 ERA and 1.48 WHIP), but he did throw well in his two major league starts this year, winning both while allowing five earned runs in 13 innings (3.46 ERA). He'll be an adequate fill-in for Stephen Strasburg, whom the Nationals insist they will soon shut down, as Washington tries to stave off the Braves for the NL East crown.

Shelby Miller, Cardinals, RHP

A poor first-half of the season -- 6.17 ERA in 77 1/3 innings -- threatened to derail the 21-year-old's rapid ascent through the minors, but he has adjusted to Triple A in the second half, with a 3.04 ERA in 53 1/3 innings. Most impressively, his 2-to-1 strikeout-to-walk ratio early in the year has been nearly 9-to-1 in his last nine starts, with 61 strikeouts and only seven walks. The St. Louis Post-Dispatch reported earlier this week that there was "strong sentiment" to promote Miller after his minor league season ends. If that happens, he'd presumably work out of the bullpen for St. Louis.

Jurickson Profar, Rangers, SS

Earlier this month team president Nolan Ryan said on ESPN Radio in Dallas that there was a "reasonable chance" Texas would promote Profar to the big leagues at some point this year. Profar, 19, and the game's No. 2 prospect, homered in the Futures Game and has breezed through Double A, with a .280/.365/.452 batting line to go with 14 homers and 16 steals. He wouldn't seem to fill an obvious need for the Rangers, however, as they already have Elvis Andrus at shortstop, designated hitter Michael Young as a back-up for each infield position and third base prospect Mike Olt already in the big leagues too. But talent can always make itself fit.

Oscar Taveras, Cardinals, CF

Taveras, the newly christened Texas League Player of the Year, slugged 22 homers with a gaudy .322/.380/.575 slash line -- not bad for a Double A player who didn't turn 20 until mid-June. The lefthanded hitter has primarily played centerfield in the minors, though he's spent notable time in the corners and could end up there permanently down the road. The Post-Dispatch reported in late July that promoting Taveras was "being talked about internally." With Matt Holliday, Carlos Beltran, Jon Jay and Allen Craig, the Cardinals already have four outfielders, so Taveras (BA's No. 18 prospect) may not get the call this year, but he has the speed and power bat to make an impact even if he's only a part-time player.

Julio Teheran, Braves, RHP

The precocious righthanded starter is only 21, yet is working on his second full season in Triple A, save for six big league appearances that haven't gone too well (5.63 ERA in 24 innings). He has a 5.20 ERA in 25 starts -- a performance reflected in his fall from No. 5 to No. 24 in the latest BA prospect rankings -- but dazzled last Saturday, allowing two hits and one run while striking out nine in eight innings. The Atlanta Journal-Constitution wrote that Braves manager Fredi Gonzalez was non-committal when asked if Teheran or fellow pitching prospect Randall Delgado might get the call, so Teheran may need a few more gems in Triple A to merit serious consideration.