Paul Kuharsky of ESPN.com reported on Monday that the deal is for three years, citing a league source. Albert Breer of NFL Network noted the contract gives the Titans "flexibility," adding that the standard agreement is for four or five seasons.

Tennessee posted a 2-7 record under Mularkey in 2015. While that mark was unimpressive, the interim coach had the thankless task of filling in for former head coach Ken Whisenhunt after the Titans started the year 1-6. The team could expect only so much progress in such a short amount of time.

"The vision Mike presented for our football team during this search as well as the character, integrity and leadership skills he displayed during the last two months of the season makes him the right coach for the Tennessee Titans," Titans controlling owner Amy Adams Strunk said, per Jim Wyatt of the Titans' official website.

On Dec. 28, Mularkey discussed the difficulty that comes with taking over as head coach in the middle of the year, per John Glennon of the Tennessean:

It was a difficult situation for a lot of people. When it all went down, there just wasn’t room for change in a lot of areas, based on where we were Tuesday, getting ready to play a game on Sunday. You’re not changing personnel, you’re not changing scheme. It is what it is. This is the way we have to move forward. For the most part, I think there’s been some progress made.

On Monday, Titans president and CEO Steve Underwood told reporters that during the process, Strunk "knew she was hiring Mularkey before interviews."

While Tennessee struggled to win games with Mularkey on the sidelines, the team did make progress on the offensive side of the ball.

In their first seven games under Whisenhunt, the Titans averaged 17.9 points per game and their starting quarterbacks threw for 228.1 yards per game. Under Mularkey, those figures improved to 19.3 and 252.9, respectively.

This move comes with some risk, though.

The 54-year-old was a head coach for three years before this season. His teams combined to go 16-32. In addition, none of those teams finished better than 20th in total offense.

Mularkey explained to reporters Monday that now that the interim tag has been lifted, he can implement changes that he couldn't previously.

"I was put in a challenging situation," Mularkey added, but he noted that he was "looking forward to a fresh start." 

The development of quarterback Marcus Mariota is paramount for the Titans going forward. Mularkey's teams sit in the 23rd percentile in passing yards and the 43rd percentile in passing touchdowns in NFL history, per Pro-Football-Reference.com.

Matt Ryan is the only quarterback who improved demonstrably under Mularkey's tutelage, and even then, most of his best seasons came after Mularkey left his post as Atlanta Falcons offensive coordinator. 

Despite that track record, Underwood called Mularkey a "quarterback whisperer."

Especially after the franchise messed up with Vince Young, Tennessee can't afford to ruin the career of another potential star QB.

Mularkey might be safe for 2016, but the Titans likely won't hesitate to go in a different direction a year from now if the team doesn't turn things around.