Appel undergoes season-ending elbow surgery

Philadelphia Phillies prospect Mark Appel will miss the rest of the season after the former top pick underwent surgery Wednesday to remove a bone spur from his right elbow, the team announced.

Appel, the Phillies' fourth-ranked prospect according to MLB Pipeline, was initially placed on the minor-league disabled list with a shoulder injury, and later injured his elbow when he restarted his throwing program, according to Matt Gelb of Philly.com. The Phillies said Appel is expected to be fully recovered in time for spring training.

Acquired by the Phillies in the five-player trade involving right-hander Ken Giles, Appel has failed to live up to the lofty expectations that followed after being selected as the No. 1 pick in the 2013 draft.

Still just 24 years old, Appel showed promise this season at Triple-A Lehigh Valley, where he authored a 1.64 ERA during April. He has since struggled though, and finishes his season with a disappointing 4.46 ERA and 1.56 WHIP across eight starts.