Cam Newton had one of the greatest NFL rookie debuts in recent memory, throwing for 422 yards and two touchdowns in a 28-21 loss the Arizona Cardinals a week ago. (Christian Petersen/Getty Images)

The superlatives have been flowing for a week about Cam Newton’s eye-catching NFL debut. His record-setting performance for the Carolina Panthers last Sunday put a dent in the widely held notion that rookie quarterbacks had little chance to succeed immediately this season on the heels of the lockout.

At least for now, he also has quieted doubters about his readiness as a passer at the professional level.

Even Newton’s staunchest supporters acknowledge the Heisman Trophy winner from Auburn still could face some typical rookie-year travails. But when the top overall draft pick takes the field Sunday afternoon in Charlotte to face the Green Bay Packers, practically everyone interested in the NFL will be intrigued to see what he does for an encore.

“I told him: ‘Great start. Congratulations. You have a building block. But you’re not going to throw for 400 yards every week,’ ” said Warren Moon, the Hall of Fame quarterback who has been a close adviser to Newton. “He could go out and have some game where he throws four interceptions. I wouldn’t be surprised if he struggles against Green Bay this week because of all the looks they’re going to give him. But as a young quarterback, you just try to be as consistent as you can and find ways to give your team a chance to win games.”

That could be easier said than done with the Panthers, who secured the right to draft Newton by going 2-14 last season and lost last weekend’s season opener at Arizona, 28-21. But Newton more than did his part by throwing for 422 yards, the most ever by a rookie quarterback in an opening game, and two touchdowns.

Former Washington Redskins quarterback Joe Theismann called Newton’s debut highly impressive but said he will wait at least a month before making any judgments about Newton’s NFL progress.

“It’s way, way, way, way too early to assess where he is,” Theismann said. “One game doesn’t make a season. One game doesn’t make a career. He has a wealth of athletic ability. Now he has the Green Bay Packers this week. Let’s see how he does against a good football team with really experienced coaches.”

Newton’s dazzling regular season unveiling came after a preseason in which he completed only 42 percent of his passes. The conventional wisdom, it seemed, was that any rookie quarterback asked to play a substantial amount this season would be in an almost impossible position after the NFL’s 41 / 2-month shutdown wiped out offseason practices and made the learning curve even steeper.

Even under better circumstances, rookie quarterbacks often have serious problems when asked to play prominent roles early on. Peyton Manning threw for 302 yards for the Indianapolis Colts in his first game in 1998 but also had three interceptions. Troy Aikman threw two interceptions and compiled a modest 180 yards for the Dallas Cowboys in their opener in 1989. John Elway completed only one of eight passes for 14 yards and threw an interception in his 1983 unveiling for the Denver Broncos.

But this also is the most passing-friendly era in NFL history, due, in part, to rule changes over the past eight years. Quarterbacks set a single-week league record for net passing yards last weekend, and Newton had plenty of company in carving up opposing defenses. New England’s Tom Brady surpassed 500 passing yards and Drew Brees of New Orleans and Chad Henne of Miami also topped 400 yards.

“I don’t go into each game, you know, trying to top anything because if I go into it like that, I think my man Tom Brady takes the whole prize,” Newton told a group of reporters crowded around his locker at midweek. “What he did a couple days ago, it was nuts. I just go into each game just being coachable and just taking the things that I’ve been practicing all week and find a way to get comfortable.”

Moon said that Newton was able to focus on passing fundamentals during the break between the final preseason game and the regular season opener, and that he benefited from having top wide receiver Steve Smith in the lineup after Smith had been sidelined for half the preseason. But Moon had been a vocal supporter of Newton’s all along, even before the draft, when some analysts were questioning whether Newton’s passing skills were sufficiently refined for the NFL.

“I never would have stuck my neck out there like I did unless I knew what type of player he was and what type of person he was,” Moon, who now runs a sports marketing company, said in a telephone interview. “I got to spend a lot of time with him and I got to know him pretty well. I got to see his work ethic. Everyone has seen the physical gifts. I could tell how hard he was working to be an NFL player. All he could do in college was what he was allowed to do in his offense.”

The Packers’ defense could present Newton with a tougher test than Arizona’s. Still, the defending Super Bowl champs didn’t have an overpowering defensive performance in their opener. They allowed Brees to pass for 419 yards before they stopped the Saints at the 1-yard line on the final play of a 42-34 triumph.

Packers Coach Mike McCarthy said last week that Newton runs the ball effectively but first looks to pass when he moves out of the pocket in response to defensive pressure. McCarthy likened the rookie’s improvisational skills to those of Ben Roethlisberger, the two-time Super Bowl winner for the Pittsburgh Steelers. Roethlisberger and the Steelers lost to the Packers in last season’s Super Bowl.

“He’s a tough guy to bring down,” McCarthy said at a midweek news conference. “He’s a big, athletic individual, a lot like Roethlisberger. . . . I think Cam Newton is also an exceptional runner with the football. He’s made people miss.”

Moon calls Newton a “special” player. Others are taking a wait-and-see approach when it comes to consistent NFL production by Newton.

“I’m tickled he got off to a good start,” Theismann said. “That always makes you feel good for a while. But let’s give it some time.”