Rays pitcher Alex Cobb has been diagnosed with tendinitis in his arm following his start Tuesday, reports The Tampa Bay Times.

Cobb left the game with tightness in his right forearm and went for an MRI. Cobb is likely to miss a few games, including possibly Opening Day.

"If it was something I was really concerned of, I probably wouldn't have thrown today at all," Cobb said. "This was something I knew about."

Pitching coach Jim Hickey feels it was mostly a precautionary move to take Cobb out Tuesday.

"At this point, any starter coming out of the game with forearm tightness is not good, so this is certainly not good," Hickey said. "But I really thought it was more precautionary than anything else on his part, which is also good because he can be stubborn and want to just go through it."