.@Titans QB Marcus Mariota ruled out for Sunday— Jim Wyatt (@jwyattsports) October 23, 2015
This really isn't a surprise. Marcus Mariota said earlier in the week that he hoped to be ready to play on Sunday, but it always sounded like it was a long shot after the (reported) Grade 2 MCL sprain.
Mettenberger is a capable back-up. He is going to throw the ball downfield a lot, assuming the offensive line gives him time to do so. This would be a great spot for the Titans to let Dorial Green-Beckham play about 75% of the snaps. His skill set pairs well with Mett Show's skill set. If you are into the daily fantasy thing, DGB could be a sneaky play in tournaments this weekend. He is cheap and won't be owned by very many people.