Mariota exited moments before the break and was evaluated during hafltime. He was officially declared questionable to return with an elbow injury and Gabbert remained under center to begin the second half.
Mariota injured his elbow earlier in the year and was dealing with discomfort regarding a pinched nerve. He missed Week 2 but has played in eight of nine games this year.
The Titans are trailing the Colts 31-3.