Courtney Hawkins

We're just past the halfway mark of the 2013 Major League Baseball season and well past the midway point of the Minor League Baseball season. While taking stock of the top prospects from around baseball, a number of names appear in the "disappointment column," which is not surprising given the general volatility of young players. Below, we take a look at some of the prospects having disappointing seasons, as well as some educated guesses as to what might be ailing them.

Matt Barnes, RHP, Red Sox: Barnes' season hasn't been as bad as some of the other players on this list but it's still been a disappointing 2013 for the right-handed hurler. The former first-round pick was expected to zoom through the minor leagues and possibly even help the big league club this season, but he currently has a 5.32 ERA with 78 hits allowed in 67 2/3 innings at the Double-A level. As the Boston Globe's Julian Benbow explained, Barnes has been working on fleshing out his secondary pitches this season so he doesn't have to rely so heavily on his low-to-mid-90s fastball.

Trevor Bauer, RHP, Indians: Bauer is the perfect example of the volatility of prospects. Selected third overall in the 2011 amateur draft, the right-hander out of UCLA dominated competition during his first taste of pro ball but the wheels fell off the wagon towards the end of 2012. Bauer's issues — both on and off the field — lead to an offseason trade and continued into 2013. His results at Triple-A have been less than ideal. After his most recent disastrous big league start, the young pitcher was returned to the minors and — according to a piece by Sheldon Ocker of the Akron Beacon Journal — he may focus on pitching exclusively from the stretch as a starter.

Kaleb Cowart, 3B, Angels: Los Angeles doesn't have a very deep minor league system whatsoever so when their top prospects stumble, it hurts them more than most organizations. The young third baseman is hitting just .215/.280/.309 at Double-A this season and some adjustments he made during the springtime could be to blame for his slow start. As Alden Gonzalez of MLB.com explained, the switch-hitting Cowart quieted his stance and eliminated the leg kick from the left side of the plate. He's still hitting just .198/.261/.275 versus right-handed pitching so clearly there are more wrinkles to iron out.

David Dahl, OF, Rockies: Like Bauer, Dahl's value is down as a result of well-documented off-the-field actions and maturity concerns. But those aren't the only things that have gone wrong for the outfielder in 2013. In early May, Dahl suffered what was expected to be a pulled hamstring while running the bases. About a week later, though, the prospect revealed on Twitter that his hamstring had been torn and was much more serious than first reported. That halted his season after 10 games (He got off to a late start because of the maturity issues mentioned above) and he hasn't appeared in a game since that time. His timetable for a return to the game is still up in the air.

Billy Hamilton, OF, Reds: Hamilton, 22, hasn't had a terrible year but he has yet to build off of the momentum he created last season when he hit .323/.413/.439 in High-A ball and stole 155 bases between two minor league clubs. Promoted to Triple-A to begin 2013 after spending just 50 games at the Double-A level, the speedy Hamilton has struggled to find his footing at the plate. On the plus side, the shortstop-turned-outfielder has nabbed 50 bases in just 80 games. His stolen base total could become much higher once he improves upon his .300 on-base percentage.

Courtney Hawkins, OF, White Sox: Hawkins has experienced a lot of struggles in his first full professional season. After hitting a combined .284 between three levels during last season's debut, he's batting just .191/.273/.485 with 95 strikeouts in 55 games during 2013. Scott Merkin of MLB.com talked to Hawkins regarding the learning curve he's experienced in High-A ball and how he plans to come out ahead.

Bubba Starling, OF, Royals: Starling opened 2013 with huge expectations surrounding him, but he hit just .195/.263/.379 with a massive strikeout rate in April. As Danny Wild of MiLB.com explained, things got so bad that Starling was sent to have his eyes examined for possible LASIK surgery in May — similar to what the Rangers did with third base prospect Mike Olt. Dick Kaegel of MLB.com later updated the story to report that the outfield prospect underwent the procedure on May 16. In June, after the eye surgery, Starling improved to hit .250/.327/.369 for the month, but he continued to strike out at a similar rate. He also hit jut one home run in 24 games. Clearly, there is more work to be done.

Kyle Zimmer, RHP, Royals: During the first three months of the year, Zimmer posted an ERA of more than 5.00 despite showing the same strong repertoire that caused him to be chosen fifth overall during the 2012 amateur draft. Thankfully, the right-hander may have finally turned a corner in July. He's posted a 2.77 ERA with no walks and 20 strikeouts in 13 innings. On the season, he's now whiffed 103 batters in 84 2/3 innings of work. Jonathan Raymond of MiLB.com spoke to Zimmer, who stated that he's finally becoming comfortable with his pitching mechanics, which is in turn allowing him to provide more consistent command.

A number of prospects have also suffered significant loss in value due to serious injuries. The list of walking wounded include: Dylan Bundy, RHP, Orioles; Travis d'Arnaud, C, Mets; Danny Hultzen, LHP, Mariners; Casey Kelly, RHP, Padres; Hak-Ju Lee, SS, Rays; and Arodys Vizcaino, RHP, Cubs.