The news that Andrew Luck had suddenly retired broke midway through the Jets’ preseason game against the Saints on Saturday night at MetLife Stadium, and the message it delivered had nothing to do with the Jets losing 28-13 or anything that took place in the tedious slop-fest that was marred by 31 accepted penalties.

In the wake of the Colts franchise quarterback, one of the stars of the league, walking away at age 29, the message was a profound one for Jets and Giants fans: Hug your franchise quarterback today.

Because you never know.

The Jets have Sam Darnold, who entering his second season already has begun to show himself as a potential star, and they hope he will be their quarterback for at least the next decade, helping them unseat the Patriots in the AFC East and perhaps even win a Super Bowl.

Same for the Giants and their rookie first-round pick Daniel Jones, who’s waiting to take over for veteran Eli Manning. Giants fans are hoping — expecting — Jones to become the next Manning and man the position for the 15 years like Manning has while winning two Super Bowls.

The news of Luck’s retirement hit several Jets players hard as they learned what went down once they got into the locker room after the game.

“It sucks for the NFL to lose such a talented player, a guy who was Comeback Player of the Year last year,’’ Darnold said after the game, in which he completed 8 of 13 passes for 97 yards and a TD. “We were looking forward to seeing him play great football this year. It’s a bummer for the whole league.’’

Jets defensive tackle Steve McLendon, who played against Luck as a Steeler and a Jet, called the news “very stunning,’’ adding, “It has to be tough for him to do, because I know an athlete like himself does not want to walk away from the game that early and that soon — especially when you have so much talent.

“Hopefully, it’s one of those deals where it’s just a one-year retirement,’’ McLendon said. “I just cannot see him being done, like, forever. He’s too much of a talent, man. It’s tough to see a talent like him go.

“You just don’t ever know.’’

That’s why no one in New York should take for granted that players like Darnold and Jones will be around forever.

“When you’re in this game long enough, you appreciate everything that these guys have to go through — the hard work taking care of their bodies and staying healthy,’’ Jets coach Adam Gase said. “It’s not easy.’’

Jets center Jonotthan Harrison, who played with Luck in Indianapolis, heard the news when he got into to locker room and said, “Everyone knows he’s been dealing with something for a couple years now medically, and it’s tough to see a great guy retire.

“It’s frustrating. I’m sure it’s frustrating for him, frustrating for that organization. Of course, I wish him the best. I know he’ll be all right outside of football. That’s not an issue. But it’s tough to see a great guy like that go.’’

Jets defensive lineman Henry Anderson, who played with Luck at Stanford and in Indianapolis, said he got to know him well and planned to reach out to him. He sounded less stunned than anyone else.

“It’s a little surprising because of where he’s at in his career,’’ Anderson said. “It definitely is surprising timing, but Andrew definitely is a different guy. He’s just a really smart dude who’s got a lot of interests outside of football. I don’t know if that has got anything do with this. But it’s not as surprising as it would be if it was another person in his situation.

“He’s had the shoulder [injury] a couple years ago and his calf or ankle this year, and I know how hard he trains and how hard he pushes himself and the standard that he holds himself to.’’

Asked about Darnold and not taking anything for granted, Anderson said, “You try to appreciate the teammates that you have and get to know your teammates, because you never know how long you’re going to be with them.’’

Jets and Giants fans: Hug your franchise quarterback today.