Florida quarterback Graham Mertz will undergo an MRI and imaging testing on Sunday after suffering a lower left leg injury on Saturday night against Tennessee, a source told On3. His status for the remainder of the season has yet to be determined. The redshirt senior exited Saturday night’s 23-17 overtime loss in the third quarter, limping off the field after throwing a touchdown pass to Arlis Boardingham while backing away from Tennessee defenders. A non-contact injury, Mertz landed awkwardly after throwing the touchdown pass and limped off the field. He returned to the sidelines in the fourt…