Mariota suffered a stinger that caused him to be removed from last week's game against the Indianapolis Colts.
Mariota was limited in practice on Wednesday, only throwing during the individual portion of practice. On Friday, he took all of the reps and seemed to have no issues throwing the ball, according to Vrabel, who also said Mariota feels good and has to keep working.
"I would imagine that Marcus is going to be the starting quarterback after being not limited, and full, and probably hope to start," Vrabel said. "It looked good today, but that's why you practice. You try to always improve and get better."
Mariota's injury was initially feared to be connected to the elbow injury that limited him during the first few weeks of the season, even causing him to miss Tennessee's Week 2 win over the Texans.
Offensive coordinator Matt LaFleur said he was pleased with Mariota after watching him take all of the reps in practice on Friday.
"To be honest with you, I couldn't really tell that anything was wrong. He looked good to me. He was a full go and he's ready to roll," LaFleur said.