Bieber dealt with right forearm fatigue toward the end of this season, Mitch Bannon of The Athletic reports.
It's not clear exactly when the issue popped up for Bieber, who was the last Blue Jays hurler to throw a pitch in Game 7 of the World Series against the Dodgers, serving up a go-ahead home run to Will Smith in the top of the 11th inning. General manager Ross Atkins said Monday that Bieber is "in a strong position" and the righty being ready for Opening Day is "a very realistic outcome." While the concern for Bieber doesn't currently seem to be high, the forearm issue and past Tommy John surgery surely weighed into the pitcher's decision to exercise a $16 million player option rather than test the open market. More should be known about Bieber's health status during spring training.