Manager Cito Gaston said an MRI would be performed Tuesday, adding Litsch was "a little sore" in his last start.
With no outs in the fourth inning, Litsch went ahead in the count 0-2 on Delmon Young before he slowly walked around behind the mound. He was visited by the trainer and removed from the game, holding his right arm against his body. Brian Tallet came in to pitch for Toronto.
"I didn't see anything wrong," catcher Rod Barajas said. "It seemed his velocity was a little down, but other than that I had no clue."
Litsch (0-1) was struggling for the second straight start, allowing seven hits and four earned runs in three innings, including a home run to Jason Kubel.
He allowed five runs on seven hits -- including a career-high three home runs -- in six innings of a 5-1 loss to Detroit last Wednesday.