Everyone in the Jets’ draft room had their eyes fixed on the TV screens.

This was Thursday night and the Browns were on the clock with the No. 1 pick in the NFL draft. The stories had circulated all day the Browns would take Oklahoma quarterback Baker Mayfield, but the Jets were skeptical. They still expected the Browns to take USC star Sam Darnold.

Then, they saw Mayfield pick up his phone. The Browns had taken the Heisman Trophy winner.

A buzz went through the Jets’ room. Darnold might actually make it to the Jets. But the Giants could still take him or trade the pick.

The Jets had their representatives at the draft in Arlington, Texas, on speakerphone. Those reps had their eyes fixed on the Giants’ table, waiting to see if they picked up the phone, indicating a trade.

“Anything happening?” someone asked from the Jets’ draft room.

The Giants turned the pick in fairly early. Now, the Jets’ brass started to dream about Darnold. Penn State running back Saquon Barkley picked up the phone. The Giants were taking him.

Jets general manager Mike Maccagnan turned to his left and looked at Brian Heimerdinger, the team’s vice president of player personnel, and said, “Oh, my God. He just fell to us.”

Maccagnan got up and walked over to where coach Todd Bowles and owner Christopher Johnson were sitting and told them he was taking Darnold.

Then, he wandered to the back of the room. A few guests had been invited to sit in the draft room. There were two elementary school-aged kids. Maccagnan sat down next to them and told them he was taking Darnold, what did they think? After voicing their approval, they got fist bumps from the Jets GM.

Heimerdinger yelled from the front of the room, “Can we turn in the pick?”

Turning in the card ended a long evaluation process for the Jets. Through conversations with people inside and outside the team, The Post retraced the Jets’ steps through that process. Here is how it unfolded:

Oct. 27, 2016: Los Angeles Memorial Coliseum

Maccagnan was attending the Cal-USC game to scout Cal quarterback Davis Webb and a few of the senior Trojans.

A friend of Maccagnan’s on the USC staff saw him in the end zone and asked him who he was scouting. His friend pointed to Darnold, who would not be draft eligible for another year.

“Hey, that’s the guy right there,” the friend said. “He has IT.”

Maccagnan filed it away, but the 2018 draft was still far in the distance and he knew a lot could change.

Sept. 16, 2017: Los Angeles Memorial Coliseum

Darnold was no longer an unknown. He entered his redshirt sophomore season as the most hyped prospect in the country after a brilliant performance in the Rose Bowl against Penn State.

Maccagnan attended five of Darnold’s games — against Western Michigan, Stanford, Cal, UCLA and this one against Texas. Maccagnan buys a ticket right behind the bench when he’s scouting a quarterback to watch how the QB interacts with teammates and coaches on the sideline and to get a view of how the ball comes off his hand.

Just before halftime, Darnold found running back Ronald Jones for a 56-yard touchdown pass. The play showed Darnold’s ability to find the right guy at the right time. USC went on to win 27-24 in double overtime with Darnold showing a calmness rarely found in a 20-year-old.

After the game, a TV crew interviewed Darnold on the field. Maccagnan hung around to watch. Darnold showed how humble he is, complimenting his team and said his teammates made some great plays. The coolness he showed on the field continued off of it.

March 17, 2018: Florham Park

The Jets had spent months breaking down the college quarterbacks. They studied the quarterbacks with film packages by situations: under center, shotgun, when blitzed, in the red zone, etc. Darnold’s ability to make plays while under duress stood out to the Jets, as did his accuracy.

Kirk Cousins had spurned the Jets earlier that week. They felt comfortable with a number of the quarterbacks and decided to try to make an early trade to beat other teams to it. While Maccagnan traveled to Pro Days at Oklahoma to see Mayfield and UCLA to see Josh Rosen, Heimerdinger hammered out a trade with the Colts for the No. 3 pick, happy to hold on to their 2019 first-rounder.

The Jets believed the odds of Darnold being available at 3 were slim, but there was a chance.

March 28: The USC campus

Those long odds felt even longer after Darnold’s Pro Day. Browns owner Jimmy Haslam sat in the stands with Darnold’s parents.

Maccagnan, Bowles, offensive coordinator Jeremy Bates, director of college scouting Matt Bazirgan and linebackers coach Mike Caldwell were all at USC that day. The Jets were impressed with Darnold, who was nearly perfect despite a driving rainstorm.

It was what happened before the workout that really stood out to the Jets, though. Darnold actively cheered on his teammates in other position groups who did drills before him. He was relaxed and confident. Unlike some quarterbacks who go through a long warm-up routine, Darnold threw a few passes and then started the workout. It was as if nothing fazed him.

The Jets contingent walked away saying, “We’ll never see him again.”

April 15: The USC campus

There was some debate inside the Jets whether they needed to conduct a private workout with Darnold, the feeling being he was certain to go No. 1 to Cleveland. Ultimately, they scheduled one.

The Jets — Maccagnan, Bowles, Bates and Bazirgan — flew out the night before.

On that Sunday morning, the Jets put Darnold through a workout that consisted of 160 passes. He had three wide receivers and a tight end to throw to. After the field session, they went to a classroom, where Bates grilled him on the whiteboard. He passed every test.

April 17-18: Florham Park

Two days after the workout, Darnold was in New Jersey. He visited the Giants on Monday and Tuesday and then had dinner with the Jets on Tuesday night, followed by a day at the team’s training center on Wednesday.

On Tuesday night, they went to Maccagnan’s favorite restaurant — “Jockey Hollow” in Morristown. Johnson and Bates sat on either side of Darnold with Bowles, Bazirgan and Heimerdinger also at the table.

The more time the Jets spent with Darnold, the more impressed they became. He had a presence about him the Jets loved.

After the dinner, Bowles said: “I love him, but it’s a waste of time. He’s going No. 1. He ain’t going to be there for us.”

Nine days later, he was there for them. They called Darnold and Johnson had one message for him: “Dude, you’re going to love New York.”

The Jets had their guy.