Mariota suffered a knee injury against the Dolphins.

Christopher Hanewinckel USA TODAY Sports

Tennessee Titans rookie Marcus Mariota will not play Sunday against Atlanta as he recovers from a sprained MCL in his left knee. Zach Mettenberger will start at quarterback.

Coach Ken Whisenhunt said Friday that Mariota has been ruled out after missing practice all week.

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Mariota sprained the medial collateral ligament in his left knee when hit low by Miami defensive end Olivier Vernon in last week's 38-10 loss to the Dolphins. Mariota stayed in the game wearing a brace.

Mettenberger started six of the seven games he played last season as a rookie. The sixth-round draft pick out of LSU still is looking for his first career win.

The Titans (1-4) also will be without wide receiver Harry Douglas (ribs) and starting cornerback Perrish Cox (hamstring).