Oviedo, formerly Leo Nunez, had been on the restricted list since August 2011, and just finished serving an eight-week suspension handed down this May for playing under a false identity. After attaining his visa in late May, Oviedo returned to Florida from his home in the Dominican Republic and reported to the Marlins' facility in Jupiter, where he worked out and served his suspension before starting a Minor League rehab stint.
The rehab stint was cut short on July 14, when the right-handed reliever exited an appearance for Triple-A New Orleans with discomfort in his right elbow. An MRI exam revealed Oviedo had a sprained ulnar collateral ligament in his throwing arm.
Due to the injury, Oviedo likely won't be available to pitch this season for the Marlins. He becomes a free agent at the end of the season, and chances are he won't return to the Marlins in 2013.