Raul Chavez was recalled from Triple-A Las Vegas to take Barrett's place on the 25-man roster.
Barrett could be out for more than the 15 days, however. General manager J. P. Ricciardi said it's possible that the injury could be more complicated than a torn muscle.
"There could be some type of fracture, we don't know," Ricciardi said. "I don't think it's a big fracture, but when the swelling goes down, we'll have a better idea."
Ricciardi could not say for sure how long Barrett will be out.
"It just depends on the swelling," Ricciardi said. "He told me he can move it a certain way. It's going to be a minimum of two weeks, but I think it will be longer than that."
After two weeks, Barrett, 32, will be re-evaluated. In seven games this season, he is batting .211 with one home run and two RBIs. He was signed to a Minor League deal on Dec. 29.
Chavez, 36, is 1-for-7 this season with Las Vegas. He was signed to a Minor League deal on Dec. 22.
Larry Millson is a contributor to MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.