Crimson Tide coach Nick Saban says Black was injured in Sunday's open practice at Bryant-Denny Stadium.
The 5-foot-11, 178-pounder was the nation's No. 2 receiver prospect coming out of Jacksonville, Fla., according to ESPNU. Black enrolled in January and went through spring practice.
Saban says Black "was doing extremely well" and "wants to play so bad he can't see straight."
Black was among a group of highly rated wide receiver signees for the defending national champion Crimson Tide, which is seeking to replace leading receivers Marquis Maze and Darius Hanks.