The Toronto Blue Jays traded for Sergio Santos to be their closer in part because he's really good, but also in part because he has a team-friendly contract. So the short-term isn't the only concern for the team, which is why they've shut Santos down for the next four weeks with a shoulder injury. From MLB.com:

"Ten to 14 days of no throw, and as we've used the typical rule of thumb, it's going to be at least the same number of days to get back to where he left off," Blue Jays manager John Farrell said. "That's going to take us right up to, probably, a four-week period."

The original fear was that Santos had suffered a serious injury to his throwing shoulder, but an MRI revealed no structural damage, so the team is taking the rest and rehabilitation route. The Jays will use experienced closer Francisco Cordero in the interim.