Rasmussen was placed on the 15-day injured list with a left hamstring strain Wednesday, retroactive to June 12, Neil Solondz of the Rays Radio Network reports.
Rasmussen was listed as the starter for Thursday's game against the Yankees but will be unable to take the mound due to his hamstring injury that will keep him sidelined for at least two weeks. The right-hander was dominant in late April and early May but struggled recently, posting a 5.59 ERA and 1.60 WHIP in 19.1 innings over his last four starts. The Rays haven't yet indicated who will take Rasmussen's place in the rotation, but Ralph Garza should be a candidate to pitch multiple innings Thursday after he was recalled Wednesday.