Brandon Morrow has an entrapped radial nerve in his right forearm and is likely out for the rest of the season a source told sportsnet.ca Wednesday night.

The Toronto Blue Jays right-hander visited Dr. James Andrews earlier in the day where the renowned specialist confirmed a diagnosis made during two previous exams by other doctors in May and June.

Despite that the team has continuously described the injury in vague terms and while speaking with reporters Wednesday general manager Alex Anthopoulos said “at some point we’ll get to the bottom of this I don’t know when.”

Radial nerve entrapment can occur when people repeatedly pronate and supinate the arm motions typical to pitching. Symptoms can include discomfort in the forearm the issue Morrow complained of and can extend into the elbow or wrist.

Such injuries typically don’t show up on MRIs which is why the Blue Jays have said all the previous tests on Morrow have shown is inflammation something unrelated to the nerve problem and more typical to what most pitchers have during the season.

A course of treatment is being finalized – at this point surgery isn’t being considered an option – and is likely to include an extended rest period that will prevent him from being ready before the season’s end.