The young would-be franchise quarterback brings renewed hope. The hype and the hyperventilation that engulfs him, from fans, from media, know no bounds. He is hailed as The Next (fill in the name of a long-lost icon). He is The Man Who Would Be King, Prince Charming, The Savior of a woe-begotten franchise desperate to be saved.

But as a romance blossoms between a bright-eyed California kid, too good to be true in every way, and a long-suffering fan base so susceptible to love at first sight, a warning light should be blinking and a caution flag must be raised:

Don’t expect miracles from Sam Darnold.

When the regular season begins, defensive coordinators will have a jolting treachery and chicanery waiting for Darnold.

Back when then-Dolphins coach Jimmy Johnson was preparing for Peyton Manning’s losing three-interception debut in 1998, he said, “We’ll welcome him to the NFL. I imagine he’ll see a few things he hasn’t seen before.”

They all do. Even the great ones encountered potholes on the road to Canton.

Manning (26 touchdowns, 28 interceptions) completed a career-low 56.7 percent of his passes as a rookie. John Elway (47.5), Terry Bradshaw (38.1) and Troy Aikman (52.9) were similarly humbled. Eli Manning (48.2) sat behind Kurt Warner for the first nine games in 2004.

Darnold has offered compelling evidence that he is not your typical rookie. Nothing seems too big for him, and nothing seems to bother him.

But he’ll still be a rookie when he starts the season on “Monday Night Football” in Detroit on Sept. 10.

Browning Nagle had thrown two passes as a Jets rookie in 1991 before orchestrating a 5-0 preseason in ’92 … before his seven touchdowns and 17 interceptions led to a nightmare 4-12 season that had then-coach Bruce Coslet asking old Bengals ally Boomer Esiason to save him.

Then there’s this: Darnold doesn’t have an Odell Beckham Jr. to take a 10-yard slant to the house. He won’t have a Saquon Barkley running or catching out of the backfield to bail him out of trouble. He won’t have a Nate Solder protecting his blind side. He doesn’t have a tight end like Evan Engram to target down the seam.

There will be no Pro Bowlers in Darnold’s huddle. No elite talents. The tight end can be a young quarterback’s best friend, but who exactly is the tight end? The wide receivers each bring something different to the table, but can Robby Anderson stay on the straight and narrow, and build on the dynamic promise he displayed last season? The offensive line is suspect and will probably struggle to find cohesiveness early. The running backs won’t cause defensive coordinators sleepless nights.

There will be growing pains. There always are for rookie quarterbacks. Darnold has checked all the intangible and character boxes, otherwise coach Todd Bowles would not have unleashed him to compete for the starting job with Teddy Bridgewater, who needs to be traded, and Josh McCown.

The impending start of the Sam Darnold Era is a feel-good story that has energized a franchise and a fan base that hasn’t celebrated a championship in 50 years. For them, Darnold represents that elusive light at the end of a dark tunnel that — fingers crossed — isn’t an oncoming train of regret.

Joe Namath (18 TDs, 15 INTs) was 3-5-1, but won AFL Rookie of the Year honors in 1965. The Jets weren’t ready to start winning until 1967, when they went 8-5-1. The Darnold Jets aren’t ready to start winning.

Darnold will get a honeymoon period (at least until his first interception). You will likely hear the 21-year-old tell us his expectations of himself are higher than anyone’s expectations of him. And maybe that will be true. But New York isn’t exactly known as a patience-is-a-virtue town. Mark Sanchez (12 TDs, 20 INTs) had a better team surrounding him as a rookie than Darnold has now. Geno Smith (12 TDs, 21 INTs) did not.

If Darnold didn’t check the mental toughness and resiliency boxes, Bowles wouldn’t think about throwing him to any wolves. But Darnold hasn’t been knocked down and bloodied yet. He will be. Many “welcome to the NFL” moments are waiting in ambush for him. How he responds will define him.

He won’t be Dwight Gooden, 1984. He won’t be Derek Jeter, 1996. He won’t be Aaron Judge, 2017. He won’t be Joe Namath, 1968.

It’s the dawn of a new day. Let the sun shine in.

Just don’t expect miracles from Sam Darnold.