Gregg Williams potential return to coaching in the NFL has been one of the big story lines during Pro Bowl week. It's expected that the Titans will bring him on as their new assistant head coach, but if you watched the Titans in 2012, that role could expand quickly once the season gets started.
The Titans fielded a very mediocre team during 2012, and their coaching fit right along with it. Jerry Gray, Tennessee's defensive coordinator, somehow managed to retain his job despite an inability to find any kind of rhythm with his defense throughout the season. Mike Munchak bringing Gregg Williams in as an assistant puts Gray on notice.
Even though Mike Munchak has two years left on his contract, it would almost certainly take a playoff run for him to keep his job past 2013. If something isn't right early in the season on defense, Gregg Williams would be up to speed and ready to take over should Munchak decide to dismiss Gray.
The alternative to the Williams-replacing-Gray scenario ...