The Tennessee Titans have finalized their coaching staff in 2020, with one glaring omission. Tennessee chose not to replace the retiring Dean Pees as defensive coordinator, as head coach Mike Vrabel did not name one for the 2020 season. Who will call the plays on defense? Vrabel explains that it will be a collaborative effort and he will be at the forefront.

"I am going to try and do what is best for the team," Vrabel said, via the Titans website. "I would say to bring in a guy who hasn't been in our system and done what we have done in Houston or here isn't what I want to do.

"So whoever calls the defense, we are going to do pretty much what we have done. We are going to continue to add and enhance things. ... I want guys that are loyal, that are great teachers and good developers."

The Titans did hire Jim Haslett as their inside linebackers coach and has plenty of experience as a defensive coordinator in the NFL. Haslett's best seasons as a defensive coordinator came with the Pittsburgh Steelers, who finished in the top-15 in points in yards allowed all three years he served in the role (1997 to 1999). The 64-year old Haslett has also served as a defensive coordinator for the New Orleans Saints, St. Louis Rams and Washington Redskins. Haslett was also the Saints head coach from 2000 to 2005, compiling a 45-51 record and winning a division title in his first season.

"I have known Jim (Haslett) since my rookie season at Pittsburgh (Haslett coached Vrabel with the Steelers) and was impressed with how he taught and developed the players on our defense," Vrabel said. "We are excited to enhance our defensive staff and be better teachers and developers of our players."

On the opposite side of the ball, several NFL teams have decided to go against hiring an offensive coordinator in favor of a passing game and run game coordinator in recent seasons. Vrabel is taking that unique approach to defense, as it's unclear who will call the plays for the Titans.

Perhaps the defensive game plan will be a group effort, especially since Vrabel served as the defensive coordinator for the Houston Texans and will combine his knowledge with Haslett's over the course of the offseason. The Titans defense finished 11th in points allowed per game (20.6) and 22nd in yards allowed (368.1), but they were tied for 10th with 23 takeaways.

Vrabel's experiment will be interesting to see play out, especially if the Titans defense improves in 2020. It could be the start of a new trend for defensive head coaches in the NFL.