Pinkston was hospitalized in 2012 with blood clots in his lungs and he recently battled the ailment again. Pinkston may retire.
Pinkston started 24 games in three seasons with the Browns, who drafted him in the fifth round in 2011 from Pittsburgh.
The 26-year-old posted a note on Twitter to thank Cleveland fans ''for all the thoughts & prayers. It's been a honor to be a part of the city!''
Pinkston started all 16 games as a rookie. He made six starts in 2012 before he had to undergo surgery to remove the blood clots. He played in only three games last season because of a severely sprained ankle.
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