The Blue Jays transferred Thornton (elbow) to the 45-day injured list Thursday, Shi Davidi of Sportsnet.ca reports.
Though Thornton is expected to avoid surgery after he exited his Aug. 23 start with right elbow inflammation, his move to the 45-day IL will nonetheless spell an early end to his season. Before being shut down, Thornton made three starts for the Blue Jays, giving up seven runs on 15 hits and three walks in 5.2 innings. The transaction clears a spot on the 40-man roster for Taijuan Walker, whom the Blue Jays acquired from the Mariners on Thursday to bolster their rotation depth.