NASHVILLE, Tenn. >> Tennessee quarterback Marcus Mariota had surgery today for his broken right leg, and Titans officials say the procedure is “considered a success.”

The Saint Louis alum had surgery in Charlotte, N.C., to place a plate over his broken right fibula.

The Titans confirmed tonight that Mariota was out of surgery. The Titans placed him on injured reserve Tuesday, and Mariota will need four to five months of rehabilitation. Mariota finished with a 95.6 passer rating that ranks third in franchise history and he is the first quarterback in team history to post back-to-back seasons with a passer rating of 90 or better.

With Mariota breaking his right leg in last week’s 38-17 loss to Jacksonville, that means veteran quarterback Matt Cassel will make his first start of his 12th season in the Titans’ finale on Sunday against the Houston Texans.

“I wouldn’t anticipate much change in the offense,” said Cassel. “We’ve had a lot of success this year doing what we do, and obviously there’ll probably be some elements of our game plan that change just based on my skill set based on what Marcus has to offer.”

Tennessee’s playoff hopes ended last weekend in a combination of the Titans’ loss and the Texans (9-6) beating Cincinnati. The Titans (8-7) are playing for the franchise’s first winning record since 2011 and a divisional win to set the tone for 2017.

Cassel has gone from Tom Brady’s backup in New England to a high-priced starter in Kansas City.

Over the past four seasons, he has started games for Minnesota in 2013 and 2014 and eight of his nine games played with Buffalo and Dallas last season. He is 1,530 of 2,598 for 17,137 yards with 102 touchdowns and 78 interceptions.

The Titans signed him this offseason to serve as the experienced peer to advise and assist Mariota’s development, which Cassel was happy to do after having gotten so much help from Brady at the start of his career.

Titans coach Mike Mularkey said Cassel is just one of the great signings by first-time general manager Jon Robinson.

“He’s just been great for our football team, great for Marcus, I think,” Mularkey said. “We’ve got a lot of guys in this locker room that we’ve added that show how to come to work and do things and how to prepare, and then when they get their opportunities, they have a lot of confidence in them.”

Mularkey also made it clear that Cassel running is something the Texans don’t have to worry about in preparing to defend Tennessee.

Cassel came off the bench last week and threw for 124 yards and a touchdown. The last time he played against Houston, Cassel threw for 201 yards with three touchdowns and a 122.9 passer rating.

That was Oct. 17, 2010, when Cassel was with the Chiefs as part of a Pro Bowl season.

Houston coach Bill O’Brien knows Cassel well from their time together in New England.

“The guy’s a really good player, smart guy, great guy,” O’Brien said. “We have an idea of what he’s all about as a player, but within their scheme, I would say it’s tough because he just hasn’t played that much. There’s definitely a lot of unknowns going into the game.”