Pryor had missed almost the entire season already after tearing his latissimus dorsi muscle in April. He had made seven scoreless appearances out of Seattle's bullpen up to that point. The triceps problem is a new injury altogether, however.
The Mariners had started Pryor on a minor league rehab stint July 16 in the hopes that he would soon return to bolster a bullpen that is currently second last in the majors with a 4.67 ERA. However, he felt pain in his triceps while warming up for an appearance on Friday. An MRI revealed concerning damage to the area.
The Mariners will have Pryor re-evaluated by a specialist in triceps injuries. The Mariners have ruled out any return in 2013 for the pitcher.
Pryor is in his second major league season. He appeared in 26 games for the Mariners in 2012, posting a 3.91 ERA.