Matt Kawahara of the Sacramento Bee tweets that Oakland Athletics right-handed pitcher Jarrod Parker "just came off the mound yelling in pain after throwing a pitch." The incident does not appear to be as alarming as the one where Parker went to the ground in pain after breaking his medial epicondyle while on rehab with the Nashville Sounds in 2015, but it appears to be a huge setback for Parker.
Parker was facing #Athletics hitters on back field. He walked off the field immediately and is talking to trainers
— Matt Kawahara (@matthewkawahara) March 10, 2016
Mood around field is stunned.