PHOENIX — The quarterback for the Giants, for more than the past decade and for the present, is Eli Manning. The quarterback of the future, the eventual replacement for Manning, is … Geno Smith?

“I can’t see why not,’’ coach Ben McAdoo said Tuesday at the NFL owners meetings.

Whoa.

“We’re a long way to go from there,’’ McAdoo said, verbally pumping the brakes just a bit. “To me, Geno, you look at it, you study the guys coming out, you study Geno, I think he’s right in the mix of one of the better players available this year.’’

There it is. The Giants look at Smith — the reclamation project cast aside by the Jets, signed to a modest one-year contract — as possessing as much value as, or more value than, the top quarterbacks available in this year’s draft. General manager Jerry Reese and co-owners John Mara and Steve Tisch have acknowledged that Manning, at 36 years old, will not last forever and that the organization has to start thinking about his successor.

There is no need, McAdoo said, to “necessarily have to go chasing that or looking for that, but if somebody’s there, you fire away, you take him.’’

Perhaps the Giants already have taken him. Smith, despite all his mental and physical scars from his four years with the Jets — he is coming off a torn ACL and will be limited in the spring — is just 26 years old.

“You take a look at Geno, he has a compact throwing motion, you like his profile, he has a quick release, gets it out of his hand, a ton of arm strength, he’s mobile, so it will be interesting,’’ McAdoo said.

“I find it very exciting. A guy who has his skill set is hard to find. You can’t find guys out there that have that type of arm talent, the quick release, the throwing motion and the feet to go with it. And he’s a competitor. It’s exciting to bring a guy in and work with a guy like that. See where you can take him.’’

For now, Smith, whose record as a starter is 12-18, will battle re-signed Josh Johnson for a backup role behind Manning. As for the issues Smith had with his Jets teammates — who can forget he was punched out and suffered a broken jaw after IK Enemkpali teed off on him — McAdoo said the Giants will take care of Smith.

“I have a lot of confidence in our locker room, and when we bring guys in, we’re very confident they’ll acclimate well,’’ McAdoo said. “I told Geno he has a clean slate.’’

As for the offseason acquisitions, McAdoo said he was impressed with the size of Brandon Marshall: “He almost didn’t fit through my doorway when he came into the building. He’s a big man. He’s like a tight-end body out there.”

McAdoo was taken aback by the girth of offensive lineman D.J. Fluker.

“Fluker’s a big man, he can block out the sun,’’ McAdoo said. “Brandon almost didn’t fit through my doorway. Fluker didn’t, he had to turn sideways to get through the doorway.’’

Another big man, Ereck Flowers, again appears destined to start at left tackle, despite a miserable 2016 showing. McAdoo said the playoff loss to the Packers was one of the best games Flowers played all season.

“I’m pretty confident he’s working very hard right now at being a better player, putting a lot of time and effort and energy into it this time of year,’’ McAdoo said. “You get to see his face a lot, he’s in and out of the building a lot. I know he loves the game and I have a lot of confidence in Ereck.’’

Like Smith, Marshall, 33, arrives from the Jets, and the hope is he can be a positive influence on the younger receivers, especially Odell Beckham Jr. McAdoo, though, did not cast Marshall in a mentor role.

“We didn’t sign him to be a leader,’’ McAdoo said. “We signed him to be a football player for us.’’