A's right-hander Jarrod Parker injures his elbow yet again

MESA, Ariz. (AP) Trying to come back from a series of elbow injuries, Oakland pitcher Jarrod Parker hurt his elbow yet again on the 12th pitch of a simulated game Thursday.

The A's said Parker, who came off the field in pain, suffered a lateral elbow impingement Thursday and will undergo an MRI exam.

Parker had Tommy John surgery in March 2014 and was slowed by a broken elbow last year. The right-hander, who twice had the ulnar collateral ligament reconstructed in his pitching arm, was nearing his return from that second Tommy John surgery last season when he was injured while on a rehab assignment with Triple-A Nashville. He had another surgery for an elbow fracture May 19.

A's athletic trainer Nick Paparesta said Parker's latest setback was not related to his last surgery. Parker was throwing to hitters for the first time Thursday since the procedure.

On the 12th pitch of his simulated game, Paparesta said Parker experienced discomfort in his elbow but that subsequent tests showed it was not as serious as last year's injury.

''We're optimistic that things go well,'' Paparesta said. ''We just want to make sure everything is right before we proceed.''

A's team physician Dr. William Workman explained that the discomfort was ''all localized to the outside of his elbow, and whatever the source is is why we want the MRI.''

In terms of a setback, Paparesta said there's no timetable and that nothing will be formalized until the MRI is studied.

''We have to make sure he has a full range of motion before we can slowly build up to throwing again,'' Paparesta said.

Parker, who has family in town, was not available for comment.

The 27-year-old Parker, a first-round draft pick of the Arizona Diamondbacks in 2007, has not pitched in the majors since the 2013 AL Division Series. He is 25-16 record and once went a team-record 19 straight games without a loss.