Activated off the 60-day disabled list before the game, Niemann was pitching for the first time since May 14, when he left a start at Toronto with a fractured right leg after being struck by Adam Lind's line drive. He went 2-3 with a 3.88 ERA in seven starts before the injury.
Niemann appeared to be suffering discomfort as he walked around the mound after Rajai Davis flied out to begin the fourth. Manager Joe Maddon and trainer Ron Porterfield came to the mound for a brief chat, and Niemann walked back to the dugout accompanied by Porterfield.
J.P. Howell came on for the Rays, who led the Blue Jays 4-0 at the time.