Rasmus has been dealing with a pulled groin in recent days, Marc Topkin of the Tampa Bay Times reports.
The injury has prevented Rasmus from appearing in Grapefruit League games since his spring debut back on Feb. 25. The 29-year-old is attending camp as a non-roster invitee, so if he doesn't get over the groin issue quickly, his chances of winning an Opening Day bullpen gig may rapidly diminish.