Contreras (head) is not in the starting lineup for Monday's game against the Angels.
Contreras was evaluated for concussion following Sunday's 5-4 win over the Reds after his head collided with Stuart Fairchild on a tag at home plate in the ninth inning. With Contreras out for the series opener Monday, Gary Sanchez will start behind home plate and bat eighth against Halos right-hander Jose Soriano.