X-factor: A running Mariota gives Titans another dimension

Tennessee Titans quarterback Marcus Mariota passes during an NFL football practice Tuesday, Jan. 2, 2018, in Nashville, Tenn. The Titans are scheduled to play the Kansas City Chiefs Saturday in an AFC wild-card playoff game. (AP Photo/Mark Humphrey)

NASHVILLE, Tenn. — Tennessee offensive coordinator Terry Robiskie might have been the happiest person at practice watching quarterback Marcus Mariota look like, well, Mariota.