Juan Carlos Oviedo has surgery

Miami Marlins relief pitcher Juan Carlos Oviedo, also known as Leo Nunez, underwent Tommy John surgery on Thursday and is expected to miss most of the 2013 season, his agent told ESPNdeportesLosAngeles.com.

"We hope everything comes out well and Juan Carlos can return toward the end of next year or in 2014", said Oviedo's agent, Andy Mota, Thursday from Pensacola, Fla, where Oviedo underwent the operation with Dr. James Andrews. "Relatively, Tommy John surgery has become a common procedure from which most pitchers come back."

In May, he was suspended eight weeks by MLB for age and identity fraud. He was eligible to participate in extended spring training and was eligible to return to the major leagues on July 23.

The 30-year-old did not pitch in 2012. Oviedo was caught playing under the fake name of Leo Nunez and spent the offseason in the Dominican Republic clearing up his immigration status. He was cleared to return to the United States in May, but injured his elbow during a minor league rehab assignment.

Oviedo's future is uncertain as he will become a free agent at the end of this season. He has an 18-20 record with a 4.34 ERA and 92 saves in seven seasons with Kansas City and Miami.