Florida starting quarterback Graham Mertz left Florida’s 23-17 loss to the Tennessee Volunteers with an apparent knee injury and was unable to return to the game. Florida head coach Billy Napier was asked about Mertz after the game “Obviously Graham played phenomenal in the game. I thought he was lights out. Really prepared well and came to play,” Napier said after the game. “He does have an injury, a lower-body injury. Obviously, we’ll give you some updates on that when we get to next week. It was significant enough that he couldn’t complete the game.” Mertz was playing well on the road in fr…