NASHVILLE, Tenn. - Tennessee quarterback Marcus Mariota's season is over. Titans interim head coach Mike Mularkey says it's "not worth the risk" of playing the rookie in their season finale Sunday at Indianapolis.

Mariota had tested his sprained right knee both Monday and Tuesday.

Mularkey says Mariota is not as far along as they thought he might be Wednesday. So the Titans (3-12) have decided to play it safe and bench him for the final game.

Zach Mettenberger will start his second straight game and fourth this season. He is 0-9 as a starter.

Mariota finishes his rookie season with 2,818 yards with 19 touchdowns and 10 interceptions despite being sacked 38 times this season. He completed 62.2 percent of his passes and has a 91.5 passer rating.