Tennessee Titans' 2018 free agency: Xavier Su'a-Filo adds competition at left guard

A breakdown of the Tennessee Titans' 2018 free-agent signings.

Xavier Su'a-Filo, G

The Titans are signing guard Xavier Su'a-Filo, who played the last four seasons with the Houston Texans. Here's a closer look at the signing:

Grade: C-plus. Su'a-Filo was a big disappointment during his time in Houston after the Texans took him in the second round of the 2014 draft. The Titans get a higher grade than expected here because they are buying low on a player with the tools and athleticism to still make an impact. Su'a-Filo won't be guaranteed a starting job, and he shouldn't be, but his addition will add more competition for incumbent Quinton Spain at left guard.

What it means: The Titans aren't sold on Spain being their starting left guard yet as they switch to a new scheme. All their moves have signaled as much, but this could be the final step that makes it apparent. Spain, if he eventually signs his low-tender offer, Su'a-Filo and free-agent signing Kevin Pamphile will all fight for the right to start at left guard. Su'a-Filo started much of the last three seasons for the Texans, but he needed a change of scenery and the hope of a new team getting better play out of him.

What's the risk: Well, Su'a-Filo was one of the lowest graded guards in the NFL by Pro Football Focus in each of the last two seasons. So, the risk is he doesn't get better and the Titans just signed a poor guard. That risk is mitigated a bit by the heavy competition at the position.

Blaine Gabbert, QB

The Titans are signing Gabbert, who played last season with the Arizona Cardinals. Here's a closer look:

Grade: C. The Titans finally found their backup quarterback. It's not a signing that will draw much excitement because of Gabbert's play, but it's at a very important position given starter Marcus Mariota's health history. Gabbert, a former first-round pick, has carved out a career as a journeyman backup. He has flaws in his game, but he's a better fit for this offense than former backup Matt Cassel.

What it means: As in previous years, the Titans should hope that Mariota doesn't have to miss much time. Gabbert beat the Titans and Jaguars as a backup last season, which certainly helped him get this job. He should be an upgrade over Cassel, but Tennessee might still look at adding another long-term backup in the draft.

What's the risk: Well, the risk is that Gabbert just can't cut it enough to win when he has to play. The Titans had that issue last season with Cassel losing in Miami. Gabbert has finished with a completion percentage higher than 59.0 just once and has a 55.9 career average. He has thrown about as many touchdowns as interceptions in his career (44 to 43).

Kevin Pamphile, OL

The Titans are signing guard/tackle Kevin Pamphile, who played the past four seasons with the Tampa Bay Buccaneers. Here's a closer look:

Grade: B. It's a solid signing for the offensive line's depth, and the type of move that could make an impact if injuries occur later in the season. Pamphile has plenty of experience (33 starts in four seasons) and Titans GM Jon Robinson knows him well as he was a part of the Bucs front office that drafted him in the fifth round in 2014.

What it means: Pamphile likely will compete with incumbent Quinton Spain, and potentially a rookie draft pick, for the left guard job. He'll also provide insurance for right tackle Jack Conklin, who is recovering from a late-season torn ACL. He has the athleticism to fit well in the Titans' zone-blocking scheme. Pamphile also connected with Mike Vrabel well in his visit to the Titans facility, and it helped him make the decision to sign in Tennessee.

What's the risk: There are some holes in Pamphile's game that could be exposed if the Titans plan to make him the starter at left guard. His versatility is his biggest asset, but he may be a better as a sixth offensive lineman on a contender than a no-doubt starter.

DaQuan Jones, DE

The Titans re-signed defensive end DaQuan Jones, who played the past four years with the team. Here's a closer look at the signing:

Grade: B-plus. It was a big plus for the Titans to prevent Jones from getting away in free agency. He's not the biggest name or best player, but he's a consistent starting defensive lineman who handles a lot of the dirty work to let the playmakers stay clean.

What it means: Jones was having his best season before a torn biceps ended it in early December. He's a big boost to the Titans' run defense. He ensures Tennessee returns its starting defensive line and can focus on adding depth or improving rather than replacing a key position.

What's the risk: Jones is coming off a torn biceps so there will always be a risk that he doesn't recover to be the same player he was before the injury. The 26-year-old is playing a position where strength is essential, and he might have to miss some offseason time.

Josh Kline, OL

The Titans re-signed right guard Josh Kline, who played the past two years with the team, to a four-year, $26 million deal. Here's a closer look at the signing:

Grade: B. The Titans probably could have tried to upgrade at this position, but it likely would have cost them much more to do so given the bloated offensive line market. It's a solid deal for both sides to retain a flawed yet durable starting-caliber guard and protector for Marcus Mariota, and they avoided having to start anew.

What it means: The Titans are one step closer to having offensive line continuity for the third consecutive season. Kline fits in well with the Titans' offensive line and should benefit from the switch to a zone-blocking scheme. Solidifying the offensive line was arguably the Titans' biggest priority coming into free agency, and the Kline re-signing helps ensure Mariota steady pass protection.

What's the risk: Kline doesn't have any huge risks other than he probably won't become anything more than a solid guard. He's had some struggles as a run-blocker, and he probably was one of the weaker points on a strong Titans offensive line.

Dion Lewis, RB

The Titans are signing running back Dion Lewis, who played the past two years for the New England Patriots. Here's a closer look at the signing:

Grade: C-plus. The Titans needed a player with Lewis' skill set to complement starter Derrick Henry, but it was a bit surprising that they spent top-10 running back money to do so. Lewis was a matchup nightmare in 2017, and he could be again in 2018 in the Titans' offense. Tennessee hopes his magic and durability don't disappear after leaving New England.

What it means: Next year's Patriots-Titans contest will be full of reunions (see Malcolm Butler below). Lewis eclipsed 1,110 total yards last season despite being part of a tandem backfield in New England. The Titans could certainly use his playmaking ability. Henry and Lewis could quickly become of the NFL's best running back duos because of their different styles and ability to get yards after contact.

What's the risk: Lewis, who entered the NFL in 2011, played 16 games for the first time in his career last season with the Patriots. His smaller stature leaves him more susceptible to injury. It could be an interesting dynamic to see how the Titans manage the workload between these two backs as Henry has been waiting two years for his workhorse back opportunity.

Malcolm Butler, CB

The Titans will sign CB Malcolm Butler, who played the past four years for the New England Patriots. Here's a closer look:

Grade: B. The Titans made their splash signing to improve their secondary and continued reshaping the team along the Patriots Way. This is a big move in hopes of taking the Titans' defense from decent to really good, and we'll soon see if Butler is worth the top-10 cornerback money they will be paying him.

What it means: Butler gives Tennessee a No.1 cornerback to complete a strong cornerback trio with last year's top free-agent signing and former Patriot Logan Ryan and 2017 first-round pick Adoree' Jackson. Ryan and Butler are friends and worked well together in New England. Butler is a Pro Bowl cover corner and the Super Bowl XLIX hero with his game-clinching interception. The Titans ranked 25th in pass defense in 2017, but that should change in 2018. On paper, the Titans should have the AFC South's second-best cornerback group, behind Jacksonville's, and a worthy set of defenders to challenge receivers within the division like DeAndre Hopkins and T.Y. Hilton.

What's the risk: Butler was in the news for all the wrong reasons over the past few months, most notably his puzzling benching during the Super Bowl. Locker-room chemistry will be huge under a new coach. The good news is Titans general manager Jon Robinson has the Patriots connections to find out the true story there. Butler also took a step back on the field in 2017, and the Titans are betting on getting the 2015 or 2016 version of the corner.