Contreras was batting in the bottom of the seventh inning when he drove the ball into left-center field and took off running down the first base line. While running, Contreras immediately pulled up limping, appearing to hold his right leg.
Contreras was immediately removed from the game and replaced by catcher Victor Caratini.
After the game, manager Joe Maddon confirmed that Contreras suffered a hamstring injury, and said that the catcher will have an MRI on Monday.
The injury comes nearly two years to the day since Contreras suffered a pulled hamstring during the 2017 season. That injury knocked the catcher out of action for exactly a month, derailing what looked to be a potential surge for NL MVP honors.