McClanahan suffered a triceps injury during Saturday's Grapefruit League game against the Red Sox, Ryan Bass of FanDuel Sports Network Sun reports.
McClanahan was in visible pain after making a pitch in the third inning of Saturday's contest, immediately calling for a trainer to pull him from the game. The 27-year-old lefty will undergo imaging on his triceps Sunday, at which point we'll have a better idea of his chances to start the Rays' season opener Friday against the Rockies.