Dahl was in centerfield for Double-A New Britain and was racing in to make a sliding catch on a blooper when he crashed into second baseman Juan Ciriaco. Dahl stayed down for several moments before being taken to a hospital, where he underwent surgery.
There's no timetable for Dahl's return, the team announced Friday. Zach Wilson, the senior director of player development for the Rockies, said in a statement that the organization wishes him ''the best as we help him toward his recovery.''
Dahl was selected with the 10th overall pick in 2012. He's hitting .269 with three homers for the Rock Cats this season.