The Post Sports Live crew put themselves in Mike Shanahan’s shoes and debate whether the Redskins head coach should start a less-than-100% Robert Griffin III over backup quarterback Kirk Cousins this week in Cleveland. (The Washington Post)

There were enormous hopes for Andrew Luck and Robert Griffin III on NFL draft night in April when they walked across the stage at Radio City Music Hall in New York, one after the other, with all the promise of someday becoming the league’s next standout quarterbacks.

But who knew then that it all would happen so quickly, that by mid-December of their rookie seasons they would be mentioned in most valuable player conversations and would have their teams in the thick of playoff contention? And who knew that this NFL draft would yield another quarterback, Russell Wilson, who would play at something resembling a Pro Bowl level right away in his debut season?

It simply is not the way it usually happens in the NFL.

As the regular season winds down, it has become clear that this will be remembered as a year of remarkable exploits by rookie quarterbacks. In addition to Griffin, Luck and Wilson, others such as Brandon Weeden of the Cleveland Browns and Ryan Tannehill of the Miami Dolphins are plowing through the more standard rookie-year ups and downs but showing potential to be reliable quarterbacks.

“So far I’ve been blown away by how well these rookies have stepped in and done,” said Marv Levy, the former Hall of Fame coach of the Buffalo Bills. “I mean, Peyton Manning went 3-13. Troy Aikman went 1-15. Brett Favre was let go by Atlanta [and traded to Green Bay]. Steve Young was let go by Tampa Bay [and traded to San Francisco]. It doesn’t happen very often this quickly.”

In a season of rookie quarterbacks, it will be a day for rookie quarterbacks Sunday in Cleveland, when the Washington Redskins attempt to continue their playoff push. The Redskins, who will be seeking their fifth straight victory, will be without the services of Griffin, ruled out a week after suffering a mild sprain of the lateral collateral ligament in his right knee. Fellow rookie Kirk Cousins will step in to oppose Weeden, the Browns’ starter.

It usually is virtual blasphemy, by NFL standards, for a group of quarterbacks to be compared to the famed 1983 class that produced Hall of Famers John Elway of Denver, Dan Marino of Miami and Jim Kelly of Buffalo. It perhaps is too soon to even bring up the more recent standard, the 2004 class of Pittsburgh’s Ben Roethlisberger, the New York Giants’ Eli Manning and San Diego’s Philip Rivers.

But maybe it is not unthinkable to believe that this quarterback class at some point could achieve a similar stature. Levy, who coached Kelly, doesn’t dismiss the possibility.

“I think it’s a very unique group,” Levy said. “To see Russell Wilson and RGIII and Andrew Luck come in and play the way they’ve played, it’s very impressive. To begin to think this group could someday earn its way to being compared to that ’83 group with Jim Kelly and Elway and Marino, it actually makes some sense.”

‘The game has changed’

When the Indianapolis Colts drafted Luck with the top overall selection and the Redskins took Griffin second in April, it was far from a certainty that both would end up succeeding as NFL quarterbacks — not just immediately, but ever. The history of quarterbacks being chosen first and second in the NFL draft suggested it was more likely that one would succeed and the other would fall short of expectations, as with Drew Bledsoe and Rick Mirer in 1993, Peyton Manning and Ryan Leaf in ’98 and Tim Couch and Donovan McNabb in ’99.

Instead, Griffin is tied with New England’s three-time Super Bowl winner, Tom Brady, for the league’s best passer rating, at 104.2, and has the Redskins a game out of first place in the NFC East and a game behind the front-runners in the NFC wild-card chase. Luck is eighth in the league in passing yards and has the Colts in the AFC wild-card lead at 9-4. Griffin and Luck have generated some consideration as MVP candidates even in a strong field that includes Brady, the Packers’ Aaron Rodgers and Manning, now in Denver.

The surprise has been Wilson, a third-round pick by Seattle who seemed destined to be a backup as a rookie because the Seahawks had made a high-profile signing of quarterback Matt Flynn in free agency. But Wilson won the starting job and has been masterful, with 20 touchdown passes, only nine interceptions and the sort of knack for producing at big moments also demonstrated by Luck and Griffin. Wilson is the league’s seventh-rated passer and has the Seahawks tied with Chicago for the NFC wild-card lead at 8-5.

“Prior to last season, it was kind of unheard of for a rookie to come in and have as much success as they had,” said London Fletcher, the Redskins’ veteran linebacker. “You think about what Cam Newton did last year, what Andy Dalton did last year, those guys coming in and playing so well early. But now it’s been duplicated. You look at Robert, Andrew Luck and Wilson out in Seattle, those three guys are playing really good football for their teams right now. I guess the game has changed a little bit where teams are more willing to throw a guy into the fire right away and not put him on the bench for a couple years like they used to in the past.”

Newton broke Peyton Manning’s NFL rookie record for passing yards last season, but his Carolina Panthers went 6-10. Dalton got the Cincinnati Bengals into last season’s playoffs as a rookie. But his play wasn’t prompting talk that he already was an elite NFL quarterback.

So the immediate impact being made by Luck, Griffin and Wilson seemingly is a blend of a group of special quarterbacks arriving in the NFL at once, at a time when teams are willing to turn things over to youngsters and adjust as necessary to make it all work. It is, after all, the most passing-friendly period in the sport’s history. More than ever, any team that doesn’t have a quarterback capable of putting up big numbers in the passing game needs to find one, and quickly.

“You’re seeing more quarterbacks come in the league with more background on how to play quarterback,” Browns Coach Pat Shurmur said. “That’s a long way of saying that they’re better prepared for our game. You’re seeing guys coming out of college basically working with drop-back schemes. You’re seeing guys with great skill and ability as far as running that are involved in option-type schemes. Then you’re seeing a little bit of a merge there.”

‘Things are trickling up’

Indeed, part of it is the NFL adapting to young quarterbacks, rather than just forcing young quarterbacks to adapt to the NFL. To take advantage of Griffin’s varied talents, Redskins Coach Mike Shanahan and his son Kyle, the team’s offensive coordinator, created an offensive system for him that mixes elements of traditional NFL offenses (a West Coast passing game, the zone blocking and “stretch” running plays always employed by Mike Shanahan-coached teams) with ingredients more closely associated with the college version of the sport (the pistol formation, triple-option running plays).

So Griffin hasn’t exactly been playing the offense that he played while in college as the Heisman Trophy winner last season at Baylor. But he hasn’t had to completely relearn everything, either.

“Things are trickling up,” Shurmur said. “You’re seeing more college-type concepts from a running-game standpoint as it applies to quarterbacks like RGIII, Cam Newton and Colin Kaepernick [San Francisco’s starter as a second-year pro] and those types of guys who have the ability to run the football extremely well.”

Shurmur said “time will tell” whether this quarterback class goes down as historically superb. But it’s clear that Griffin and Luck, in particular, already have elevated their teams as rookies.

As Mike and Kyle Shanahan pointed out before the season, the traditional method for teams to win with rookie quarterbacks was to have a strong running game on offense and a very good defense — in effect, minimize the young quarterback’s role by having an overpowering team around him. That was the formula followed by the Steelers with Roethlisberger in 2004, by the Baltimore Ravens with Joe Flacco in 2008 and the New York Jets with Mark Sanchez in 2009 — and, to a lesser extent, by the Atlanta Falcons with Matt Ryan in ’08.

The Seahawks are giving Wilson such support, ranking in the top five in the league in rushing offense and total defense. But Griffin and Luck have not benefited from being on powerhouse teams. The Redskins run the ball well, in part thanks to Griffin, but are ranked 28th in the NFL in total defense. The Colts are 22nd in both rushing offense and total defense. The heavy lifting on each of these winning teams is being done by its rookie quarterback, and that is an extreme rarity in the NFL.

“You don’t expect that,” Levy said. “But there’s always the exceptions to the rule.”