The Seattle Mariners are shutting down top pitching prospect Taijuan Walker for at least a week after exams revealed right shoulder inflammation.

Manager Lloyd McClendon said Friday that Walker flew to Los Angeles to have a second opinion on the shoulder, which has limited him during spring training.

Walker was examined by Dr. Neal ElAttrache at the Kerlan Jobe Clinic in Los Angeles on Thursday. He agreed with the team's original diagnosis.

"It's a little bit of a setback, yeah," McClendon said, according to the Associated Press. "It is what it is and we've got to continue to move forward."

Walker was expected to take a spot in the rotation, especially since American League Cy Young Award finalist Hisashi Iwakuma has not thrown because of a finger injury. It is not clear yet if this setback will affect his chances.

"I think it's just normal throwing, what most pitchers experience at some point," McClendon said. "The MRIs were clean and were good. There was no structural damage with this guy so everything is fine from that standpoint."

Walker, 21, went 1-0 with a 3.60 ERA in three starts for Seattle last September.

Walker reported to camp with a sore throwing shoulder and was limited to throwing off flat ground.