It's a question even current Titans players are pondering.
Speaking after Pro Bowl practice on Wednesday, defensive lineman Jurrell Casey said he has no inkling where the team is leaning regarding an offensive coordinator, but he has a preference of style for the mobile Mariota.
"Honestly I don't know. I don't know who the offensive coordinator is going to be," Casey told NFL.com. "I don't know what type of scheme they're going to run. I'm a big fan of Marcus being in a spread type of offense. I would love to see him back in that Oregon-style type offense, that's when he did a lot of damage. I'm just waiting to see him getting into that more mobile-style."
The question for Vrabel is who could design such a system for Mariota. Ohio State offensive coordinator Ryan Day surfaced as a potential candidate, but NFL Network Insider Ian Rapoport reported Day will remain at OSU. Mariota's former coach at Oregon, Mark Helfrich, recently signed to be the Chicago Bears' OC.
While most viewed a need to change offensive scheme as the main motive behind the Titans parting ways with Mike Mularkey, Casey pointed to Tennessee losing too many close games as a key reason.
"I think the biggest thing is that too many close games where we should have beat teams undeniably," he said. "And when you have those type of games, everybody knows the business. Games were closer than we needed them to be. You need changes to make sure you get across that hump. Who knows what is going to happen next year. Who knows those close games we're going to win them. You want to put yourself in a situation where every game you're blowing teams out."
Now it's on Vrabel to take a talented Titans team to the next level. First, he must find an offensive coordinator for Mariota.