"I'm back."

That's what linebacker Jaylon Smith proclaimed to team owner Jerry Jones after the Dallas Cowboys' 20-13 win over the New York Giants on Sunday Night Football.

Despite playing in the last 18 games for the Cowboys, Smith announced his return because the real Jaylon Smith had been absent before Sunday night -- the one who was a Butkus Award winner, an honor given to the best linebacker in college football, and a consensus top-five player in the 2016 NFL draft.

Before he tore his ACL, LCL and caused damage to the peroneal nerve in his left knee during his final game at Notre Dame, Smith was one of the best athletes in football, parlaying his physical talents into becoming the best linebacker in the college game.

Think of the best linebacker prospects in recent memory -- Roquan Smith, Reuben Foster, Tremaine Edmunds and Haason Reddick, all first-round picks in the years since Smith was drafted. Before his injury in the 2016 Fiesta Bowl, Smith was a better prospect than all of them. He was a special talent, blessed with otherworldly athleticism, great instincts and unique pass-rushing ability for an off-ball linebacker.

After a mediocre 2017, many thought that Jaylon Smith was long gone. He was explosive with his linear movements, but it was painful to watch him change direction, as the drop foot condition he was suffering from because of the damaged nerve severely limited his agility. Smith struggled to change directions and opposing teams took full advantage throughout last season.

This year, however, Smith looks closer to his pre-injury self than the post-injury version.

He's not the same player he was then, significantly bulking up to handle the rigors of the NFL game -- he's more powerful, but slightly less agile. Nevertheless, after 17 games in a Cowboys uniform, the old Jaylon Smith finally showed himself Sunday night.

Smith led the Cowboys in tackles (seven solo, three assists) against the Giants, showing well in coverage and against the run. He even outplayed Sean Lee, who is widely regarded as the leader and best player on the Cowboys defense.

The Cowboys were able to limit second overall pick Saquon Barkley to just 11 carries for 28 yards, fourth-worst among running backs with at least 10 carries in Week 2, thanks in large part to Smith's efforts. Here's a great example:

Here, the Cowboys are in their base 4-3 defense with Smith as the "Mike," or middle linebacker, aligned over the play-side B-gap. Once the ball is snapped, Smith immediately reads the Giants offensive line and diagnoses their pin-and-pull run. This allows Smith to immediately flow to the play side, making it difficult for offensive linemen to get a good angle to block him once they look to the second level.

Once Barkley receives the toss, Smith does an excellent job of mirroring his movement while pursuing downhill at an aggressive 45-degree angle. From there, Smith expertly tracks Barkley's inside hip, preventing the cutback lane and forcing him to the sideline.

Notice the burst Smith uses to close the gap to Barkley -- it's reminiscent of Smith's days at Notre Dame.

Taking on blocks has been a weakness of Smith's since college; however, the added bulk to his frame has allowed him to defeat blocks with more frequency. This tackle near the line of scrimmage is a great illustration:

On this play, the Cowboys are once again in their base 4-3 defense with Smith as the "Mike." Yet this time, he is aligned over the backside A-gap. After the snap, Smith reads and diagnoses the Giants' zone run, allowing him to immediately pursue the ball carrier downhill at a 45-degree angle while maintaining his gap responsibility.

Once Smith occupies his gap, he takes on the block from the Giants' right guard:

Notice Smith's body positioning. He is in a perfect position to attack and defeat the block. He has a lower pad level while playing with the proper base. He attacks the block with the same foot and shoulder, allowing him to stay square to the ball carrier and hold his ground through the contact. Smith rolls his hips on contact, jolting the right guard backward, and makes the tackle for a minimal gain.

In the past, Smith would have been too aggressive in his efforts to avoid the block, which would have made it easier for the running back to avoid his tackle attempt as he cut back.

It's rare to see a 245-linebacker take on a block by a 300-pound offensive lineman and win. But when you combine his athleticism and added bulk, Smith can generate an abnormal amount of power at the point of attack. Here's a quick example:

Smith's effort makes no impact on the play's outcome, but check out what he does to Giants left guard Will Hernandez. Despite giving up nearly 90 pounds, Smith is able to knock Hernandez back on contact, forcing the guard to give ground, lose his footing and fall on his face.

While Smith's efforts against the run were splendid, his performance in coverage was spectacular, given his past. This play is particularly impressive:

On this play, the Cowboys are running Tampa-2 coverage with their nickel defense (four defensive linemen, two linebackers, five defensive backs). In this coverage, Smith is responsible for running with and covering any inside vertical route.

On this play, Smith is forced to turn and run with tight end Evan Engram, who clocked a 4.42-second 40-yard dash at the 2017 scouting combine, deep down the middle of the field. Despite Engram's speed, Smith is able to flip his hips and turn and run with him, allowing no separation and forcing Eli Manning to check the ball down to the shallow crosser.

There may be only a handful of linebackers on Earth who can make this play look as effortless as Smith does. Last year, Manning may have found Engram for a touchdown, as Smith's drop foot would have prevented him from fluidly flipping his hips to cover the tight end.

If that wasn't impressive enough, Smith did it again later in the game against Odell Beckham Jr.:

Here, the Cowboys are once again running Tampa-2 coverage with Smith responsible for the deep middle against any inside vertical route. After the snap, Smith does a great job of getting to the proper depth as he reads the two-man route between the Giants receivers.

Once Beckham breaks inside on his "Bang 8" route (popularized by Cowboys Hall of Famer Michael Irvin), Smith closes the gap, turns and runs with the Giants star receiver, effectively eliminating Manning's throwing window:

Still, despite Smith's tight coverage, Manning uncorks the long ball. While the ball is in the air, Smith does an excellent job of staying in-phase with Beckham, attaching himself to Beckham's inside hip. As the ball reaches the catch point, Smith looks back for the ball to avoid pass interference and leaps to defend the pass:

Even if he didn't have safety help, the ball would have been incomplete because of Smith's excellent coverage.

While there may be a handful of linebackers who can turn and run with Engram in coverage, there may only be one or two others who can turn, run and make a play against Beckham.

When the Cowboys drafted Smith at the top of the second round in 2016, this is the player the front office was envisioning -- a game-changing talent who improves the quality of the entire defense. It's not a coincidence Dallas is playing its best defense in years at the same time Smith finally becomes fully healthy.

He's not perfect by any means, as he needs to improve tackling in space, so while Smith has proclaimed his return, don't be surprised if he becomes better than he ever was in the future.

John Owning writes about NFL player evaluation for SportsDayDFW.com. Follow him on Twitter at @JohnOwning.