According to Jim Wyatt of the Titans' official website, Vrabel will be formally introduced as the team's new head coach Monday.
Vrabel told Wyatt the following:
"This is an incredible opportunity and one I have been preparing for my entire football life. I want to thank [owner] Amy [Adams Strunk], [general manager] Jon [Robinson] and the entire Titans organization for putting their faith in me. I am excited to get to work and that work starts now. We want to build a culture around winning, competitiveness and toughness. Everything we do is going to be geared towards winning and being physical. We want to prepare our players so they know what to do, which will allow them to play fast and aggressive."
Vrabel will replace Mike Mularkey, who was fired this week after leading Tennessee to a 9-7 record and a playoff berth.
The 2017 season was Vrabel's first as a defensive coordinator after he spent the previous three years as Houston's linebackers coach.
After leading the NFL in total defense in 2016, the Texans experienced a drop-off to 20th in 2017. Houston also ranked last in scoring defense at 27.2 points per game.
The absence of some top defenders played a role in the regression, though. Defensive end J.J. Watt and linebacker Brian Cushing each missed double-digit games due to injury and suspension, respectively. Also, former No. 1 cornerback A.J. Bouye signed with the Jacksonville Jaguars, which left a major void in Houston's secondary.
Despite his team's defensive struggles, Vrabel entered the offseason as a popular head coaching candidate. In addition to his four years with the Texans, he spent three seasons as a defensive assistant at Ohio State from 2011 through 2013.
Vrabel registered 57 career sacks, including 48 during an eight-year stint in New England.
He was named to one Pro Bowl and one All-Pro First Team and experienced three Super Bowl wins.
Vrabel has never been a head coach, but he spent years learning under Patriots head coach Bill Belichick, which helped make him a valuable commodity.
His predecessor, Mularkey, went 20-21 in parts of three seasons and made the playoffs once. The Titans upset the Kansas City Chiefs 22-21 in the AFC Wild Card Round on Jan. 6 after overcoming a 21-3 deficit.
The Patriots then blew them out in the divisional round, 35-14, resulting in Mularkey's departure.
The Titans offense figures to be built on running back Derrick Henry's hard-running style and quarterback Marcus Mariota's improvisational skills in 2018, while Vrabel will look to improve upon a defense that ranked 13th in yardage allowed and 17th in points allowed last season.