Mets closer Bobby Parnell has a partially torn medial collateral ligament in his elbow, the team announced. He received a platelet-rich plasma injection and will rest for two weeks before beginning a throwing program. The team says Parnell will then be reevaluated to see if he needs surgery.

Parnell, 29, allowed one run in an inning of work on Monday, blowing the save on Opening Day. He had trouble cracking 90 mph with his fastball -- the PitchFX system classified many of his fastballs as changeups -- after averaging 95+ mph from 2010-13. It was clear he wasn't right.

Parnell had surgery to treat a herniated disc in his neck back in December and was slowed a bit in spring training. The medial collateral ligament is not the Tommy John surgery ligament, that's the ulnar collateral ligament. Regardless, surgery to repair the MCL would knock him out for an extended period of time.