Thornton (elbow) was activated from the 10-day injured list ahead of his scheduled start Thursday against the Orioles.
As expected, Thornton is ready to rejoin the rotation after spending the minimum amount of time on the IL with right elbow inflammation. The right-hander will replace Ryan Borucki (elbow) -- who was sent back to the IL on Wednesday -- in the rotation. Thornton owns a 5.45 ERA, 1.54 WHIP and 100:45 K:BB in 21 starts (99 innings) with the Blue Jays this season.