New York Mets closer Bobby Parnell has been diagnosed with an incomplete tear of the medial collateral ligament in his right elbow, the team announced Tuesday.

Parnell, examined at the Hospital for Special Surgery after complaining of tightness in his right forearm following a blown save in Monday's Opening Day game against the Washington Nationals, received a platelet-rich plasma injection and has been prescribed complete rest for approximately two weeks.

The team said the right-hander is then to begin a throwing program, the outcome of which will determine whether elbow surgery will be required.

Parnell had a 2.16 ERA and 22 saves in 2013 as the Mets' closer. He missed the final two months of the season and needed neck surgery. His velocity was noticeably lower during spring training.

Veteran reliever Jose Valverde, who pitched 1 1/3 perfect innings on Monday and struck out three, will likely inherit the closer's role in Parnell's absence.

Valverde has 286 career saves in 12 seasons, leading the National League in saves in 2007 and 2008 and the American League in 2011.