Column: NFL rookie QB crop headed not by Johnny Manziel, but ... Derek Carr?

In each of the last six NFL seasons, at least one rookie quarterback has started an opener.

That trend will continue this season — although the Oakland Raiders nearly ran out the play clock before deciding.

The Raiders announced Monday that rookie Derek Carr had earned the starting job over veteran Matt Schaub for Sunday’s opener against the New York Jets. Surely, that was welcome news for fans who created the trending Twitter topic #StartTheCarr.

Schaub sat out the exhibition finale against Seattle with a sore elbow, and Carr made a convincing case for himself in a 41-31 victory. He directed four touchdown drives in four possessions — including three touchdown passes — adding an exclamation point to his first training camp.

“There were a lot of factors involved in that,” Raiders Coach Dennis Allen told reporters after practice Monday. “It’s not an indictment on Matt Schaub at all. I still feel very confident in Matt Schaub.”

Allen added that it won’t be a week-to-week decision, and “Derek’s the starting quarterback.”

Carr, a second-round draft pick (36th overall), will be the first Raiders quarterback to start the first game of his rookie season.

“He’s a tough kid, mentally,” former Raiders coach Jon Gruden said of Carr, a three-year starter at Fresno State after redshirting his freshman year. “I think he’s ready to go, and I think his performance against Seattle made it a slam dunk if you ask me.”

Gruden is the voice of authority when it comes to the rookie quarterback class as a whole. He knows Carr well, just as he knows the three first-round quarterbacks selected before him: Jacksonville’s Blake Bortles, Cleveland’s Johnny Manziel and Minnesota’s Teddy Bridgewater — none of whom is slated to start when his team opens the season Sunday.

“A lot of these kids are underclassmen — Bortles, Johnny Manziel, Bridgewater,” Gruden said in a phone interview. “I think that’s one of the reasons why their head coaches are going to be reluctant to start them right away. I think those three kids, albeit they’re good prospects . . . look, they didn’t complete their NCAA eligibility. And normally quarterbacks do that.

“They’re missing a spring practice. In Johnny Manziel’s case, he’s missing two spring practices and two regular seasons. And to be totally honest, the NCAA rules on time allowed with players is minimal now, so you’re not getting fully developed triggers from college, especially when they’re underclassmen.”

That said, all four of those rookies could be starting soon enough.

The 6-foot-5 Bortles, who has drawn comparisons to Pittsburgh’s Ben Roethlisberger, has been scorching this summer, showing touch and accuracy on short, mid-range and deep passes. He completed a league-high 11 passes of 20-plus yards in four exhibitions.

The Jaguars, who open at Philadelphia, are taking their time with Bortles, even though the rookie outplayed veteran starter Chad Henne this summer. The rookie isn’t complaining about learning from the sideline, however.

“That was made clear from day one,” Bortles told reporters recently. “From the get-go, there was a plan, a big-picture thing that they had in mind and were going to do. That was to learn from Chad, figure out things and get acclimated. That’s the plan that’s been instilled the whole time.”

Manziel, the 22nd pick, made a predictable splash in the run-up to the season, but didn’t earn the starting job. His jersey shot to No. 1 on the sales charts, he played aerobics instructor “Johnny Jam Boogie” in a Snickers commercial, and he was fined $12,000 by the league for making an obscene gesture to Washington’s sideline.

There was no wavering from first-year Browns Coach Mike Pettine when it came to naming the starting quarterback. Two weeks before the regular season, Pettine announced the job would go to Brian Hoyer, who had three starts in 2013 before a season-ending knee injury.

It’s a smart move for the Browns to sit Manziel in the opener against Pittsburgh. According to ESPN, the Steelers are a league-best 17-2 against rookie quarterbacks since 2004, when Dick LeBeau rejoined the team as defensive coordinator.

But Manziel likely is one bad Hoyer game — or even one bad half — from lining up behind center. The Browns, who are particularly hurting for playmakers after All-Pro receiver Josh Gordon was suspended for the season, have their bye in Week 4, which could serve as a convenient break to get Manziel ready to play at Tennessee in Week 5.

Bridgewater, the last pick of the first round, improved by the week this summer after struggling in his exhibition opener. He threw a league-best five touchdown passes in exhibition games — tied with New England rookie Jimmy Garoppolo — and directed a game-winning two-minute drill in Week 2 of the preseason that had teammates calling him “Teddy Two Minutes.”

However, Matt Cassel won the Vikings starting job because of the way he picked up coordinator Norv Turner’s offense better than any of the other quarterbacks.

No one has a more comprehensive view of the rookie quarterback class as a whole than Gruden, who spends an entire day one-on-one with each of the top prospects for his ESPN pre-draft series, “Gruden’s QB Camp.” Each episode features one quarterback, who visits Gruden at his office in Tampa, Fla. The two break down tape, draw up plays on the white board and go through a workout at a local practice field.

In the five years he’s done the show, Gruden has mentored 37 quarterbacks, 13 of whom were selected in the first round. Fourteen of last season’s regular starters — nearly half the No. 1 quarterbacks in the league — participated in his camp, among them Seattle’s Russell Wilson, Indianapolis’ Andrew Luck, Cincinnati’s Andy Dalton, Carolina’s Cam Newton, Washington’s Robert Griffin III and Philadelphia’s Nick Foles.

“In Derek Carr’s case, I thought he had the best arm talent in the draft,” Gruden said. “He’s a senior, has taken a lot of snaps, has made a lot of throws. He’s got a pedigree with his brother [quarterback David Carr, selected No. 1 overall by Houston in 2002]. And to be honest, I think he’s the best quarterback the Raiders have had from a prospect standpoint in a while.”

Gruden points to the fact Carr stayed in school and learned his craft, rather than bolting early to the pros.

“I like finishers,” the coach said.

A finisher, and that’s just the start.

Follow Sam Farmer on Twitter @LATimesfarmer