Grilli, 40, was designated for assignment on June 27 after going 2-4 with a 6.97 ERA in 26 games for the Blue Jays. He is a 15-year veteran with nine different teams including part of 2009 with the Rangers.
Scheppers made five appearances for the Rangers since being called up on June 19. Four of the five appearances were scoreless. He allowed three runs without retiring a hitter in a 15-9 loss to the Indians on Monday.
Scheppers has options and veteran right-hander Ernesto Frieri does not. That was a determining factor in the decision, according to manager Jeff Banister.