Port Charlotte, FL (SportsNetwork.com) - Tampa Bay Rays pitcher Alex Cobb was diagnosed with tendinitis in his right forearm, an issue that will likely keep the right-hander out of a projected Opening Day start.

Cobb threw three perfect innings in Tuesday's spring training start against Philadelphia, then underwent an MRI exam because of tightness in the forearm. He will likely rest for a week before being re-evaluated.

The 27-year-old was given the nod to start the April 6 opener against Baltimore. He was 10-9 with a 2.87 ERA in 27 starts last season.