Ryan Cook said he will get an MRI on his right forearm Thursday, but the A’s reliever sounded confident that an injury suffered Wednesday is not major.

Cook left the first game of a doubleheader against Seattle with what was diagnosed as a forearm strain.

“It’s not as bad as you guys think, at least we think right now,” Cook said after Oakland won the second game 2-0.

Cook said his forearm tightened up on him after throwing back-to-back sliders to strike out Corey Hart in the top of the 10th in the opener. He left the game with two outs and runners on the corners and was replaced by Dan Otero. He said his forearm was still tight after the second game but added:

“I actually am really optimistic. Everything that goes on with Tommy John and all that stuff, (the signs) seem to be good. There’s no pain in those areas. It seems to be strictly in my forearm. So as of right now, I think -- and I can confidently say we -- are really optimistic.”