Dennis Mitchell has known Jeff Demps well enough to recognize that competitive gleam in his eye.

As Demps ran through his routine training sessions this winter for the upcoming football season, Mitchell could catch a glimpse of a guy who was running with a unique purpose.

Demps is a two-sport athlete at heart. He is neither a football player nor a track star. He has always been both.

But even when the running back committed to the Patriots last summer on a three-year contract, Mitchell and others close to Demps figured it would evolve into his singular interest.

Sometimes, though, it’s tough to leave a love behind.

“You can kind of feel things in people, and Jeff has never really left track emotionally,” Mitchell said. “So when he came out there and started working out and stuff, you could see he was starting to get the feel of it back again. But you never would think that he would make a decision like this.”

That decision was Demps’ recommitment to track for Team USA. The sprinter, who specializes in the 100 meters and was a silver medalist in the 4×100 at last year’s London Games, informed Bill Belichick on Monday that he’d continue running for his country. And Mitchell, a 1992 gold medalist himself who coached Demps in high school, got his old gig back.

Demps isn’t giving up on football, though there’s still no indication on the Patriots’ feelings toward the news. For starters, the Pats don’t begin their offseason program until voluntary workouts start in early April. The offense and defense won’t take the field at the same time until May, and mandatory minicamp is in mid-June. Demps’ camp still hasn’t clarified his plans for those camps.

As for track, well, Demps is training with Mitchell in Clermont, Fla. He works out for at least four hours per day, including up to 21⁄2 hours on the track. Demps is actually behind schedule for the impending track season. Mitchell explained the athletes at the national level begin with fall training to work on their conditioning. Demps isn’t conditioned yet.

His goal is to compete for Team USA in late March and April, but Mitchell questioned that.

“If he runs something like that, it’s going to be because his body is ready to do it,” Mitchell said. “But he hasn’t been training long enough to even make a call like that yet.”

Because Demps’ decision is still so fresh, it’s truly too early to know what will happen for him in either sport.

“The only thing I can guarantee is whenever he would report to the (Pats) team, he’s going to be in heck of shape,” Mitchell said. “He’s going to be ready to go because at this level of track and field, the physical demands of it are more than what people would normally think. It’s just not going out on the track, seeing how fast you can run and go home. Professional track and field athletes are physically capable of doing basically anything they want to do.”

And Mitchell has been close enough to Demps to know how well he can balance both sports, as well as how important each is in his life. Dual success, Mitchell believes, is sure to follow.

“If there’s anybody in the country that can do it, it’s him,” Mitchell said. “As long as there’s a possibility that this can happen for him, he’s going to give his best effort. There’s going to be a lot less adaptation to it than most people think because of the individual you’re dealing with. Jeff is the 2000’s Bo Jackson scenario. He can do everything. He’s just the new Bo. That’s what I see.”