According to Yahoo! sports, Tribe closer Chris Perez could be sidelined anywhere between 3-4 weeks because of a strained shoulder. He will not throw for the next week to 10 days.
Perez pitched an inning Tuesday during a 4-1 loss to Kansas City and felt pain in the shoulder Thursday. He said the injury is not as serious as the strain he suffered last spring to a muscle on his left side in his first bullpen session on Feb 23.
Because of the injury, Perez will not play for the United States in the World Baseball Classic. It is the second straight spring training Perez has been injured. He strained a muscle in his left side during his first bullpen session on Feb. 23 last year but recovered in time for opening day, when he allowed three runs in the ninth against Toronto in a game the Blue Jays won in 16 innings.
A "strain" to the pitching shoulder is a very vague description and the severity of the injury is just as uncertain. There are several types of strains, ranging from the Acromioclavicular (AC) strain to the rotator cuff, the latter being much more serious.
With the language being used by both Perez and GM Chris Antonetti, I would believe the injury to be closer to the AC strain, but nothing can be certain until Perez fully rests and a full assessment by both the medical and baseball staff be given after he does so.