Jermaine Grace has been living on the fringes for a while, but the other day he was right in the middle of everything when doing what he was taught and merging his instinct and skill set like an actor ad-libbing so as to improve a script.

The super athletic guy put brainpower into the equation and rocked.

When the Falcons’ third-year linebacker intercepted Josh Rosen’s pass Thursday night and returned it 19 yards to the Dolphins’ 3-yard line, a young man looked finally to be at home.

Which he was. As he said, “My rookie year, I probably wouldn’t have done that.”

Grace is from Hollywood, Fla., just north of Miami, and his pick in the second quarter Thursday was perhaps the best play of his professional career. Yes, it was in an exhibition game, but it came on a night when it looked like all his lights were turned on.

The former Miami Hurricane tied for the team lead with five combined tackles and assists, picked that pass, and broke up another pass while playing 42 snaps.

His signature play was a beauty.

In the second quarter, with the Dolphins facing first-and-20, the defensive call came for zone coverage, and the linebacker made his drop. Miami wide receiver Isaiah Ford had lined up in the slot and ran a short button hook across Grace’s face.

By the playbook, he stops his backpedal at the throw and joins Ford at the ball to break up the pass or tackle the receiver for a short gain.

Grace flipped the script largely because he wasn't thinking about it. He merged his DNA into his game, so just before Rosen cocked his arm, the linebacker broke forward.

It was all in the eyes. It was feel.

“So basically, we coached that all week. They cross (routes), sit and read the quarterback,” he said. “After that, it was just a jump. I took my practice to the game, did exactly what I what was supposed to do, read the quarterback’s eyes and just took off. No panic.”

Sure, Rosen looked the pass into Miami failure.

But somebody had to see those eyes, and Grace hasn’t been that guy before because he was all in his head all the time.

After three seasons at the University of Miami, where he made 139 tackles with five sacks in his sophomore and junior seasons, he signed with the Falcons as an undrafted free agent in 2017. He made the team, too, and played in the first five games, when all of his 78 snaps were spent on special teams.

Then, he got cut. He played in six games later that season for the Colts and then started the NFL pingpong game. The Browns signed him and cut him in the offseason. The Seahawks signed him, and kept him around long enough to play the opener in 2018, and cut him.

And the Falcons signed him again, to the practice squad, because coach Dan Quinn sees something in Grace even though he’s smallish for a linebacker at 6-feet, 223 pounds (that seems generous).

The 25-year-old man with a cool smile will not be labeled a run-stopper.

That might not be a big deal in the modern NFL. There are others designated to stop the overland attack.

Grace is a bit like Deion Jones, who is, you know, pretty good.

Perhaps he’ll graduate from the Falcons’ “Plan D” program, which is all about developing players from their practice squad. It’s clear that Grace has improved.

“He has, really through the development plan. I thought he and (offensive lineman) Matt Gono are the ones that I thought really put the work in ...” Quinn said.

“For different reasons, but he can also guard backs and so as you’re looking at third down and have a matchup when you’re looking to play man-to-man, you’re looking for players who have those kind of traits.”

Translation: Grace is competing to replace Duke Riley on the roster, and it doesn’t help Riley that he’s injured again. He’s a speed guy who can’t cover. And Grace is a speed guy who can cover, even if he’s not as stout in the run game.

“He plays mostly in our sub packages ... which is more than the base packages ...,” Quinn said. “He’s more (of a) safety (in) size, playing linebacker. He’s about 220 pounds, so he’s not a big, giant guy. He’s almost in the build of Deion.

“And both of those guys are two are our fastest linebackers; quite honestly some of our fastest players on defense, so the ability to match them up on teams and on running backs is a big deal.”

The new Grace is not like the old Grace.

He’s done his studying, and now he knows. He doesn’t have to think it; he knows it.

So, the Miami man can fly on instinct.

“I’ve got some years under my belt, so I know how the game works and I know what to look for ...,” Grace said. “If I see this look, I know exactly what’s going to happen.

“It’s no more thinking. I know what formations are going to be a run or a pass, and I look at offensive linemen’s hands, and if the runner looks around, he’s blocking, if he’s looking straight he’s probably going to run ... things like that, little things like that I didn’t see my rookie year.”