Backup Ryan Tannehill was spotted on the sideline with his helmet on in the fourth quarter, but Vrabel stuck with his starter despite Mariota's lackluster game.
"Not very (close)," Vrabel told reporters when asked if he considered replacing Mariota with Tannehill, according to NFL.com's Kevin Patra. "(Tannehill) just can hear the calls when he puts his helmet on."
Mariota, 25, completed 23-of-40 passes for 304 yards while taking nine sacks. Though the box score suggested a solid effort, the former No. 2 overall pick struggled with accuracy and failed to make a big play.
"I've got to find that out because I can't start games like that," Mariota said of his struggles. "You know, I didn't help our team at all in the first half, didn't give our guys chances to make plays and I felt I need to go out and just muster something together.
"I've got to continue to have that mentality throughout the season and just give our guys opportunities to go make plays."
After dominating the Cleveland Browns in Week 1, Tennessee has lost two straight games, scoring just a combined 24 points in those contests.
The Titans next face the Atlanta Falcons in a Week 4 road tilt.