NASHVILLE, Tenn. – One look at the Titans' Derrick Henry reveals all you need to know about why he's considered an up-and-comer in the NFL's running-back ranks.

The man is a monster, standing 6-3 and weighing 247 pounds, with the ability to generate an incredible head of steam if given the opportunity. He flew past defenders at nearly 22 miles per hour during a touchdown run against Indianapolis last season, the sixth-fastest time for any ball-carrier in the league.

Who in their right mind was really trying to get a piece of Henry as he roared through the line in that victory against the Colts?

It takes a little more investigation, however, to figure out the secrets to Dion Lewis' success.

Unlike Henry, the mere sight of the 5-8, 195-pound Lewis won't make defenders quiver in their cleats.

So just how is it that Lewis will enter the 2018 season with as much momentum as any other running back in the league, having led the NFL over the last eight weeks of last season with 625 yards – and averaging over five yards per carry?

Lewis' path to productivity begins even before the ball is snapped, according to Titans running backs coach Tony Dews.

"He's very smart," Dews said. "I think Dion dissects things pre-snap. I think he sees things pre-snap and then he reacts. He's also been in the league going on seven years and he's seen a lot of different things, been in different systems. That helps."

Lewis' preparation helps him get to where he's going – and beyond – very quickly.

According to the NFL's Next Gen stats, Lewis spent an average of just 2.7 seconds per carry behind the line of scrimmage last season, the 12th-best figure in the league. He also recorded the league's second-best efficiency number (3.3), a stat that measures how well a back travels North/South – as opposed to dancing toward the hole.

When attacking defenses, Lewis uses what might be considered a disadvantage – his height – to advantage, disappearing and re-appearing as defenders try to track him.

"Sometimes he even hides behind the line," Titans coach Mike Vrabel said. "If the line can stay on their guy and kind of cover him up, (Lewis) gets a chance to dip in there and dip out. It's very different than Derrick. You can see Derrick behind a lineman, but you really can't see Dion."

But maybe the most surprising set of numbers behind Lewis' breakout season in 2017 – he'd never before gained as many as 300 yards – was his ability to extend plays.

The diminutive Lewis finished tied for second in the NFL with an average of 2.5 yards after contact per carry. Only LeGarrette Blount – who measures 6-0 and 247 pounds – had a better yards-after-contact average at 2.6.

So who needs beef to bounce off tacklers?

"Physically we think of him as small because he's short, shorter than Derrick," Dews said. "But he also has a very strong, compact build, so he has really good balance and really good vision.

"He does a great job of getting on edges and setting defenders up. And obviously, he's strong enough and has enough power that he can finish runs as well."

Lewis brings up another difference-making factor.

"I've got a lot of heart," Lewis said. "I'm just using my size to advantage, using my leverage and my ability to make people miss – and just trying to blend all that together."

The bottom line is that Lewis' offseason acquisition should give the Titans one of the NFL's most intriguing backfield rotations.

Option one is Henry, a former Heisman Trophy winner who recorded three touchdowns of more than 60 yards last season – a 72-yard run against Indy, a 75-yard run against Houston and a 66-yard pass reception against Jacksonville.

Option two is Lewis, a smart, efficient and tough-to-tackle back who gained more yards last year (896) than in his first five seasons combined.

The pair combined for 45 gains of 10 yards or better last season – 25 by Lewis, 20 from Henry.

"I would just say we both have a lot of confidence in our abilities," Lewis said, "and we both feel like we've got something to prove."

Consider that fair warning.

-- Reach John Glennon at glennonsports@gmail.com and follow him on Twitter @glennonsports.​