Canning underwent an MRI which revealed chronic changes to the UCL and acute joint irritation in his right elbow.
The 23-year-old had the issue crop up after his spring debut Wednesday, and the diagnosis of potential UCL issues is a worrying development. He also missed the final month-plus of last season with elbow inflammation. There is no official timetable for his return and Canning will continue to be evaluated over the next couple days, but his status for Opening Day and beyond is now in question.