The Rays optioned Stanek to Triple-A Durham on Sunday.
Stanek's blazing fastball makes him more intriguing than the average reliever, but his lack of a quality second pitch hindered his success over 21 appearances in the majors last season. The 26-year-old finished with a 5.85 ERA and 1.90 WHIP in 20 innings, with much of the damage coming on the six home runs he allowed. He'll need to display more consistent success with his off-speed stuff at Durham before earning another look with the Rays.