KNOXVILLE, Tenn. (AP) — Florida quarterback Graham Mertz suffered a lower left leg injury in the third quarter of the Gators’ 23-17 overtime loss to Tennessee on Saturday night and was unable to return to the game.

Florida coach Billy Napier said Mertz will undergo further testing to determine the severity of the injury and his condition for the remainder of the season. Mertz, a redshirt senior, missed Week 2’s 45-7 win over Samford because of a concussion but returned as the Gators’ starter in the final four games.

Mertz was injured after throwing a 13-yard touchdown pass to Arlis Boardingham at 7:18 of the third quarter that gave Florida a 10-0 lead. It was a non-contact injury as Mertz appeared to land awkwardly after releasing the pass. He took a step back and immediately grabbed him by the leg before hobbling to the sideline.

After Mertz went into the injury tent, he watched the fourth quarter on crutches and with a brace on his left knee. Freshman DJ Lagway, who had made some appearances at quarterback, replaced Mertz and threw an interception on his first attempt after returning to the game, leading to Tennessee’s game-winning field goal with 1:37 left in the third Quarter .

“Obviously Graham did a phenomenal performance in the game. I thought he gave it his all,” Napier said. “He prepared really well and came to play. He actually has an injury, a lower body injury. … It was so severe that he couldn’t finish the game.”

The Gators also played much of the second half without their top running back. Montrell Johnson suffered a lower-body injury on the same drive. Mertz threw the touchdown pass after rushing for 85 yards on 12 carries. Freshman Jadan Baugh replaced Johnson.

Florida had the ball inside Tennessee’s 20-yard line four times in the first half, but only managed a single field goal and led 3-0 at halftime. The Vols, who have yet to give up more than 19 points in all six games this season, won for just the third time in the last 20 meetings between the schools. It is the first time since 1990 and 1992 that Tennessee has won two straight games against Florida in Knoxville. The Vols went 38-33 in 2022.

“I think we played extremely hard and with passion in all three parts of our team,” Napier said. “The story of the tape is certainly the missed opportunities in the first half on offense. We had a lot of opportunities to score points and left a lot of points.”