Without hesitation, Marcus Mariota is the most important player on the Tennessee Titans. Without him, the Titans are not a playoff team in 2017.

Since quarterback is the most important position in football, for this article we’re doing things a little differently. This will take a look at who I consider to be the five most important non-quarterback pieces for the Titans. The order of the countdown will go from five to one, and remember that this is just my opinion.

So with that said, let’s get the countdown started.

5. Dion Lewis

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You could insert Derrick Henry into this spot and I would not disagree. But I feel that Dion Lewis is a little more important going into the 2018 season because he adds a new dimension to the Titans offense.

Dion Lewis is more than just a third down back. He’s a guy you can trust to churn through tiny gaps on run plays, making him a quality runner in addition to a quality receiver. And as a receiver, you have all sorts of uses for Lewis, which greatly enhances your game plan if you’re an offensive coordinator.

Lewis has the quickness to give him the edge while stemming his routes, the vision to find the tiniest of holes and exploiting them (let’s be mature, here), and is also a quality blocking back. Simply put, Lewis adds all sorts of options to the Titans offense, hence his spot on this list.

4. Kevin Byard

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After experiencing a breakout sophomore year (where he was named First Team All-Pro by the Associated Press), free safety Kevin Byard has cemented himself as the bread and butter of the Titans secondary.

Byard led all safeties in both interceptions (8) and pass disruptions (16). While some of his interceptions came on a stroke of luck, Byard’s coverage skills, ball skills and vision all took a big step up, and he established himself as arguably the best young safety in football. His interception on Deshaun Watson in week 4 is a perfect example of his ball skills and ability to undercut the target.

Byard is earning a little less than $4 million from his rookie contract. To get his high level of play from that amount of money is tremendous value for the Titans, and I’m convinced he still has more to show in 2018.

3. Delanie Walker

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Delanie Walker was a home run free agent signing for the Titans back in 2013, and that was done on a four-year $17.5 million contract. He’s given Tennessee extremely high tight end production as a result, putting up 356 receptions for 4,156 yards and 26 touchdowns, while being named to three consecutive Pro Bowls.

Walker’s hands took a step down in 2017, but he was (still) just about the only receiver the Titans had that could consistently create separation. His chemistry with Marcus Mariota has also been noted, as they’ve connected for 12 touchdowns since 2015.

In a new scheme, Walker should have a bounce back year. He’s 33 years old, but he’s also managed to stay relatively healthy, and I don’t see why he can’t have another Pro Bowl caliber season.

2. Taylor Lewan

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The highest paid offensive lineman in the NFL, Taylor Lewan, simply put, is the bread and butter of the Titans offensive line.

Lewan’s refined technique as a pass blocker has helped give Mariota many clean pockets, and he is equally as impressive in the run game. As the left tackle to a right-handed quarterback, Lewan protects Mariota’s blind side, making it easier for the quarterback to adjust to pressure and survey his reads down the field.

Tennessee’s offensive line simply isn’t the same without Lewan, but then again that’s pretty obvious.

1. Jurrell Casey

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With exception to Marcus Mariota, no player on the Titans is more important than star defensive tackle Jurrell Casey.

You can line up Casey as a 3-tech and he’s phenomenal. You can put him in the A-gap, B-gap or C-gap and he’d overwhelm the lineman on the opposite side of the ball. He’s extremely explosive off of the snap, can control the speed of his jabs with relative ease, and he’s a monster as both a pass rusher and run stopper.

The reason I have Casey as the most important non-quarterback on the Titans’ roster is simple. The Titans have made an effort to haul in younger defensive talent, snagging Harold Landry and Rashaan Evans from the same draft, drafting cornerback Adoree Jackson in 2017, and signing Malcolm Butler from New England.

Instead of being a defense intent on rebuilding, with Jurrell Casey, the defense suddenly looks like it can be a top 15 unit. Casey makes the jobs of those around him on the defensive front much easier because of his versatility. He’s been rewarded by his high quality play with three consecutive Pro Bowl appearances as well, a testament to his value for Tennessee’s defense.

So, those are my five most valuable non-quarterbacks on the Titans. With that said, who are your picks, and why?