NASHVILLE, Tenn. -- It might soon be time for the Tennessee Titans to lock up their bodyguard, left tackle Taylor Lewan.

The Titans have important pending free agents including defensive lineman DaQuan Jones, linebacker Avery Williamson and guard Josh Kline, but none comes close to Lewan in terms of long-term importance.

A new deal for Marcus Mariota would certainly outweigh Lewan, but it might not make sense for either party to do that one right now after the quarterback's rocky Year 3.

Until then, attention turns to Lewan, who is set to enter the final year of his deal and play on a fifth-year option salary worth $9.34 million if a long-term deal isn't worked out. Lewan should be the Titans' next contract extension, and it will be an expensive one.

Former NFL agent Joel Corry, a contract and salary-cap analyst for CBS Sports, says the Titans "may have to set the market at offensive tackle" with a long-term deal for the 26-year-old Lewan.

"He's definitely much better than Eric Fisher," Corry said, referring to the Chiefs left tackle who signed a four-year, $48 million extension with $40 million in guarantees in July 2016. "The offensive-tackle market doesn't make much sense right now because Russell Okung shouldn't be the highest-paid offensive tackle. You're going to have to go above that in order to get a long-term deal done. And Lewan's a guy you can't afford to lose."

Okung, who signed a four-year, $53 million deal with the Los Angeles Chargers last March without an agent, leads all left tackles with a $13.25 million average yearly salary. The Washington Redskins' Trent Williams, who is right behind Okung with a $13.2 million average, leads all offensive linemen with $41.25 million in guarantees.

Corry says the Titans might need to go over both of those figures to get a Lewan deal done.

Lewan, who was selected to his second consecutive Pro Bowl in 2017, has proved to be one of the NFL's best left tackles since being drafted 11th overall in 2014. He's the physical and vocal protector of the team, and brings a nasty streak and a brazen personality that reverberates on and off the field.

Titans vice president of football administration Vin Marino has done a good job managing Tennessee's salary cap and negotiating contracts. It's a pleasant luxury for the Titans -- a team coming off a playoff victory -- to have an expected $50-plus million in cap space.

Marino, alongside general manger Jon Robinson, will work with Tom Condon, Lewan's agent, to find a middle-ground agreement with which both parties can walk away somewhat happy.

It might work in Lewan's favor that there is a dearth of quality NFL offensive linemen, and teams typically overpay for the few who do hit the market.

"It's going to be a great free-agency year for the offensive line. You saw that position across the board go crazy last year," Corry said. "Linemen who weren't that good like Matt Kalil got $11 million a year. If he's worth that, what's Taylor Lewan worth?"

Kalil, the Panthers' left tackle, signed a five-year, $55 million extension last March. Kevin Zeitler, a guard who signed with the Browns last March, got a five-year, $60 million deal with $31.5 million in guarantees.

Lewan has missed just one game over his past three seasons in Tennessee. He can be a bit of a loose cannon -- as evidenced by on-field blow-ups which led to costly penalties, fines or an ejection -- but that shouldn't be too much of a demerit in negotiations.

Lewan did give up a few more sacks in 2017 as Tennessee's offensive line took a step back as a group. But he has typically been a consistent and athletic player who should translate well to the Titans' new zone-blocking scheme.

The Titans have a history of locking up their homegrown players, and just last August they rewarded defensive lineman Jurrell Casey with a four-year, $60.4 million extension, with $40 million in guarantees, even though Casey had two years left on his deal.

A new contract for Lewan could see him rival Casey as the Titans' highest-paid player in terms of gross money, guarantees and maybe even average yearly salary. And given Lewan's value, it would likely be worth it.