Tennessee's leader went to the locker room early on Saturday afternoon.
Titans quarterback Marcus Mariota left Tennessee's win over the Washington Redskins late in the second quarter with a stinger and did not return. NFL Network's Melissa Stark reported the stinger is in the shoulder area.
Titans coach Mike Vrabel said following the win that Mariota is "still being evaluated."
Backup Blaine Gabbert replaced Mariota just before halftime with Tennessee down 10-6 and led the Titans back to a 25-16 victory. Gabbert finished with 101 yards and one passing touchdown.
"That's why he's here," Vrabel said of Gabbert's performance. "That's his job is to be ready to go, to prepare like a starter, and then if his opportunity comes, to come in and make the most of it. Really proud of him."
Gabbert has played in place of Mariota this season -- who suffered a nerve injury in his right elbow and left Tennessee's odd Week 1 loss to Miami -- starting two games and appearing in a total of six.
Mariota took the time necessary to allow his elbow to heal, returning in Week 4 and playing through the rest of the season up to this point, save for an eerily similar departure just before halftime of the Titans' Week 11 loss to the Indianapolis Colts.
Speaking of the Colts, Tennessee (9-6) finishes the season with a critical home test against Indy (8-6) next Sunday, potentially with the No. 6 seed on the line. It remains to be seen whether Mariota will be available.
