The AFC East-leading Patriots (7-2) will be seeking their seventh consecutive victory against the Titans (4-4).
While Vrabel never coached under Belichick, he did play for him for eight years as a linebacker and obviously learned some things while playing for the legendary Patriots coach.
"I can't deny the fact I played there for eight years and we had a lot of success," Vrabel said. "Bill was my coach. He traded me to Kansas City, we didn't talk for a couple months, maybe a year.
"Then we became friends, and I used him as a resource when I started my coaching career, and still talk to him a lot now. This week we're competitors. We're always competitors as far as I'm still coaching and so is he. I guess it's unique from that standpoint."
The Vrabel connection to the Patriots is one of several with the Titans. There's general manager Jon Robinson, who was a scout in New England and now heads up the Titans' front office; defensive coordinator Dean Pees, and cornerbacks Logan Ryan and Malcolm Butler, guard Josh Kline and running back Dion Lewis.
Belichick downplayed the connections.
"We have to get ready for everybody," Belichick said. "We know Kline, and Dion, and Malcolm, and Logan," he said. "They have a lot of guys on their defense besides them. They all know us, that's the way it is every week in this league. There are always players that we had or they had. It's the National Football League."
But Belichick did speak fondly of Vrabel.
"Mike was a tremendous player. He had great work ethic, and very, very smart," Belichick said. "He's like that as a coach on the field. He can handle a lot of responsibility. He is very instinctive of the game, it came easy to him. He's a really hard working -- great condition, he can go all day.
"He took a lot of reps in practice and in the game. He never really needed to come out of the game or practice. He had great stamina. Mike is very passionate for football. He has natural leadership."
Butler has struggled with the Titans, but Vrabel hasn't yet shown signs of giving up on the cornerback, even after he gave up two touchdowns last week in a 28-14 victory over the Dallas Cowboys.
"When you play man coverage, you have to look at your man," Vrabel said. "Malcolm knows that, and we've talked about that, and we continue to practice it, we continue to coach it and we try to show it to him."
Butler addressed his woes on Wednesday.
"I just have to play my game and be more disciplined and do the little things right," he said. "It's the little things that are affecting me. I'm trying to make plays when they're not there, and I've got to be more disciplined."
Butler and the Tennessee defense have the unenviable challenge of trying to slow down Patriots quarterback Tom Brady. Two of Brady's favorite targets are wide receivers Julian Edelman (31 receptions) and Josh Gordon (22 catches since arriving from Cleveland).
Brady prevailed in a dual with Aaron Rodgers last Sunday when the Patriots came away with a 31-17 victory.
Titans quarterback Marcus Mariota completed 21 of 29 passes for 240 yards last week against Dallas as Tennessee ended a three-game losing streak. Mariota threw two touchdown passes and also rushed for another one.