Thornton will serve as the Blue Jays' bulk reliever behind opener Wilmer Font in Sunday's game against the Yankees, Blue Jays radio play-by-play broadcaster Ben Wagner reports.
Thornton has recently flipped between working as a traditional starter and primary pitcher. His Sunday work will likely begin in the second or third inning, and he can be expected to work four to five frames. Thornton has thrown the ball fairly well of late, allowing just four earned runs across his last three appearances, spanning 14.2 innings.