Bazardo was diagnosed with a right lat strain after exiting his appearance Tuesday for Triple-A Worcester, Alex Speier of The Boston Globe reports.
Bazardo will undergo additional tests before a timetable for his return is revealed, but he'll most likely wind up on Worcester's 7-day IL. The 25-year-old right-hander previously made the first two big-league appearances of his career earlier this season, striking out three over three scoreless innings of relief for Boston.