CINCINNATI -- We all knew we would be seeing Kris Bryant in the majors this season, and it was a surprise to no one when he got the call in April. What we didn't expect was the steady flurry of prospect callups that marked the season's first half. With the likes of Carlos Correa, Miguel Sano, Joey Gallo, Francisco Lindor and the injured Byron Buxton and Steven Matz already up, a second-half letdown for prospect hounds seems inevitable.

While the minors have been drained of the top major league-ready talent, there are still several prospects worthy of stashing. Most of them played in this weekend's Futures Game, which featured many of the minors' best young players. For the most part, these prospects are long shots to contribute in Fantasy this season, but then again, who thought Correa, Sano and others would have been up as early as they were?

Here's the rundown on seven prospects to keep an eye on over the coming weeks.

Aaron Nola, SP, Phillies

Including Nola on this list practically feels like cheating, since it's all but a foregone conclusion that he will be up with the Phillies by the July trade deadline. While he's been on the fast track practically ever since the Phillies selected him with the seventh overall pick in the 2014 June amateur draft, Nola's quick rise through the minors wasn't something that excited me. Through 132 combined innings in Advanced Class A and Double-A, Nola had done an excellent job of limiting walks as well as hits on balls in play, but he hadn't been much of a bat-misser.

That has changed since last month's promotion to Triple-A Lehigh Valley, as Nola has struck out 9.1 batters per nine innings and induced grounders on slightly more than half of the hit balls he has allowed. The change has occurred over a grand total of five starts, so Fantasy owners can't feel too confident that Nola has turned a corner, but the recent uptick does make his impending promotion more intriguing. On the chance that he sustains his recent improvement, Nola is worth picking up in any mixed league larger than 12 teams.

Mark Appel, SP, Astros

Heading into this season, Appel seemed close to being a lock to make his major league debut in 2015. While the Astros have needed reinforcements in their rotation, Appel has yet to get the call, and you can't blame them. While Appel was struggling in Double-A, Lance McCullers, Vincent Velasquez and Dan Straily not only earned shots at rotation spots, but each has pitched well enough to keep them.

Still, it might be premature to rule out a major league promotion for Appel. He has improved his control and had better results in general in recent weeks, and he has moved up to Triple-A. If injury strikes one of the Astros' current starters, Appel could be the next in line. Similarly, it's not outlandish to think Velasquez or Straily could struggle. Appel is far from a slam dunk to reach the majors this year, but nonetheless, he's not a bad candidate to stash in mixed leagues.

Kyle Schwarber, C, Cubs

From Javier Baez to Arismendy Alcantara to Addison Russell, the Cubs have found ways to get promising prospects into the lineup by having them play multiple positions. Even Kris Bryant has dabbled a bit in left field. Yet they seem utterly committed to having Schwarber play catcher, and that could prevent him from seeing more than a nominal amount of playing time in the second half. Miguel Montero's thumb injury could pave the way for a Schwarber callup after the All-Star break, but there is no guarantee that Montero will be out for long -- or that Schwarber would be Montero's replacement, if one is needed.

Schwarber's ability to hit for power and get on base has been evident, even during his brief callup earlier this season. Even with the risk that he spends the rest of the season in Triple-A, he's worth stashing in just about any format, if you happen to have an available reserve slot.

Corey Seager, SS, Dodgers

Seager is the one player featured here who did not participate in the Futures Game, but only because the Dodgers nixed the invitation. His torrid pace at the plate has diminished some since his promotion from Double-A Tulsa to Triple-A Oklahoma City, but given that he's a 21-year-old in the Pacific Coast League, we should probably cut him some slack. It's not as if Seager isn't still mashing. In 63 games, he is batting .287 with eight home runs and 20 doubles. His bat appears to be ready for the majors, but where can the Dodgers find room for him?

It seems highly unlikely that Seager would unseat Jimmy Rollins at shortstop, and unless Justin Turner cools off, the Dodgers would have little incentive to replace him at third base. Seager's situation is similar to Schwarber's; he offers power at a position where power is at a premium, but the odds of him finding a significant role this year don't look good. His roadblocks actually look even more insurmountable, so I'd be reluctant to stash Seager in a standard mixed league. He could certainly be viable in those formats if he does get an opportunity.

Richie Shaffer, 3B, Rays

Shaffer salvaged a miserable 2014 season at Double-A Montgomery with a strong rebound over the final month of the season, as he cut back on strikeouts and clubbed eight homers over 29 games. In hindsight, that was not merely an isolated hot streak, but a turning point in what had been a disappointing minor league career for the former first- round pick. Shaffer returned to Montgomery to begin this season, and he batted. 262 with seven home runs in 39 games before earning a promotion to Triple-A Durham. All Shaffer has done there is increase his batting average by 22 points while more than doubling his home run rate.

In a recent interview, Shaffer credited mechanical adjustments he made last season along with offseason physical training for the improvements he has made this year. He also said he learned to how to relax and enjoy the game, saying, "When you go through the struggles I went through last year, you kind of have to (relax) or it's just going to eat you up." In addition to improving his work at the plate, Shaffer has accepted the challenge of playing first base for the first time since his 2013 stint in the Arizona Fall League. That additional versatility could be just what Shaffer needs to earn his first major league promotion.

Because there is currently no clear path for Shaffer to find regular work in the majors, he doesn't need to be added outside of AL-only leagues for now. However, if he gets the call with a chance for regular playing time, his power and on-base skills would make him someone to consider in deeper mixed leagues.

Ketel Marte, SS, Mariners

Marte is owned in just two percent of CBSSports.com leagues, yet he could have a far greater impact this season than Schwarber or Seager. In his second go-around in Triple-A, Marte is putting together a nice season, batting .343 with 17 stolen bases in 20 attempts and 20 strikeouts in 198 at-bats. The stolen base total may not look all that impressive until you account for him losing more than a month to a broken thumb.

While Marte has done his part to merit a callup, Mariners incumbent shortstop Brad Miller could be helping the prospect's cause by struggling against left-handed pitchers. Marte was hitting .365 against lefties at Triple-A Tacoma before his disabled list stint, which ended just three days prior to his appearance in the Futures Game. Should he work his way into a platoon with Miller, Marte could get enough playing time to matter in mixed Rotisserie leagues, thanks to his stolen base potential.

Balbino Fuenmayor, 1B, Royals

Fuenmayor has one of the more intriguing stories to emerge from the minors this season, but if he continues to produce he could be more than just a curiosity. He languished for seven seasons in the Blue Jays' minor league system, never advancing beyond Class A, and he was released in 2013. After spending 2014 with Les Capitales De Quebec in the Canadian-American Association, Fuenmayor signed with the Royals, who immediately advanced him to Double-A. After blasting the Texas League for a .354 batting average with 15 home runs and 22 doubles in 73 games, the Royals promoted him to Triple-A Omaha.

Given his torrid hitting, improvements in his strikeout rate and power numbers and recent promotion, Fuenmayor would seem to be a candidate for a second-half callup. However, he has only played first base and designated hitter this season. Fuenmayor does have some versatility; he has played third base and outfield in the past. It may be a long shot, but just maybe if Fuenmayor stays hot in Triple-A, he could be a potential replacement for Alex Gordon (groin). Especially if he gets some playing time in the outfield, it's time to start picking him up in deeper leagues.