It’s the opener for everyone, which means that whether you are getting set to play your first game in the NFL — like Pat Chung, Ron Brace or any one of the other Patriots rookies who made the 53-man roster — or starting your 35th season in the league — like Bill Belichick — there are going to be some nerves.

“Yeah,” Belichick said when asked if he still got nervous before an opener. “I think everybody’s got the butterflies on opening day. Certainly, the coaches do.”

Well, not all coaches. This week, Belichick recalled his first game as a head coach, a 1991 contest between the Cleveland Browns and Jimmy Johnson’s Dallas Cowboys. While Belichick obsessed over the contest, the Cowboys weren’t as uptight.

“Yeah, I don’t even think we did a scouting report on you guys,” said Johnson, who would go on to win back-to-back Super Bowls starting the following season. “We were pretty concerned with that second game, not the first one.”

“He was right,” Belichick recalled with a laugh. “The score was competitive (a 26-14 win for Dallas), but it really wasn’t. They were a lot better than we were — and he knew it, too.”

Soothe any pregame nerves you may have by keeping these five things in mind when you sit down to watch the Patriots-Bills opener Monday night:

Tom Brady. He took 15 snaps in last season’s opener before Bernard Pollard went careening into his left knee. Before that, you had to go all the way back to that night in the Arizona desert against the Giants to find an occasion when he played in a game that really meant something. It has been a long journey back for the quarterback, who anticipates completing another step in the rehab process when he takes the field Monday night against Buffalo.

One thing to watch for Monday is Brady’s movement in the pocket. His pocket awareness is one of the things that has made him a truly great quarterback — his ability to move subtly from one side to another to avoid pressure and buy time is an overlooked asset. He hasn’t been forced to do a lot of shuffling in the pocket over the course of the preseason — it still remains to be seen how much his injury may have robbed him of that skill.

But if he still has it, it could be a long season for the rest of the NFL.

“I’ve played a lot of games, so it’s not like it’s the first game of my rookie season, that type of excitement,” Brady said. “I think there’s just an excitement for a new season and to see what kind of team we have and to see what kind of mental toughness we have and what kind of character we have. We’re going to be faced with plenty of adversity this year and I want to see how we respond to that. It’s always exciting to start the year, especially playing on Monday night.”

Patriots cornerbacks vs. Terrell Owens. The New England secondary is an unknown quantity, particularly the cornerback position —three of the five cornerbacks on the roster are new, and of that group only one player has seen serious time in the preseason (Leigh Bodden). And the other two have a limited sample size in the Patriots’ system.

While Bodden has looked sharp throughout training camp and into the preseason, the rest of the cornerback spot is a question. Does a 34-year-old Shawn Springs have anything left in the tank? Is Jonathan Wilhite capable of building on his strong finish to the 2008 season? Can Terrence Wheatley shake off a hideous preseason and get to where he was midway through last season? And can rookie Darius Butler contribute at all?

Springs believes the Buffalo passing game — and Owens in particular — will provide just the early season test the Patriots secondary needs. In other words, the rest of the league will know a lot more about where New England’s pass defense stands by 10:30 Monday night.

“You play a guy like that, and you see where you’re at [as a secondary], because you know he’s always going to dominate an opponent and he comes out and he works really hard,” Springs said. “The good thing about him is that you’re either going to be the bug or the windshield.”

Aaron Schobel. Remember when Tom Brady said he and Matt Light cracked open a beer when Jason Taylor left the AFC East a few years ago? While it was Taylor who gets all the pub for terrorizing Brady and Light on a twice-a-year basis, Aaron Schobel actually has sacked Brady more than Taylor has. The TCU product has sacked Brady 11 times in 14 career games against the Patriots quarterback, more than Taylor (9.5 sacks) or Joey Porter (6 sacks).

If Schobel can consistently beat Light and whatever tight end is assigned to help out on Brady’s blind side, the Bills will have a better chance at winning this game. If New England can neutralize the Buffalo pass rush — and Schobel in particular — then the Patriots shouldn’t have any problems stretching New England’s winning streak over the Bills to 13 games.

“It’s not a big trick defense,” Brady said. “They line up, play hard. They have a bunch of tough guys over there. It’s a very well-coached defense. They don’t give you anything, you’ve got to earn it. You can’t be sloppy with them. They’ll make the plays. They’ll make you pay.”

Special teams. The New England special teams unit went through a ton of changes in the offseason – new special teams coach, new special teams captain, new long snapper and new kick returner. Meanwhile, Buffalo had one of the top special teams units in the league in 2008, led by explosive return man Leodis McKelvin. The only chance the Bills have on Monday night might be to take advantage on special teams.

“They’re very good in the kicking game,” Belichick said. “McKelvin [has] hurt us on kickoff returns. He had several big ones last year. Real good coverage teams on both punts and kickoffs — [the Bills are] right at the top of the league like they usually are, good specialists, good returners. Some real good core guys in their kickoff game.”

Patriots interior defense. With the trade of Richard Seymour, New England is going to have to make some adjustments along its defensive front. When the Patriots are in a 3-4, it’ll be Vince Wilfork on the nose. In a 4-3, Wilfork will be one of the two interior linemen, along with rookie Ron Brace, and, if he’s ready to go, fellow first-year down lineman Myron Pryor. On the ends, it’ll be Ty Warren with a healthy dose of Jarvis Green, Derrick Burgess and Tully Banta-Cain.

On the plus side for New England, if you still have questions about your defensive front, this is the game where you can work them out —Buffalo is starting three rookies on its offensive line, something that has most all the Bills concerned.

“There’s a lot of worry,” said Buffalo coach Dick Jauron when asked about the offensive line. “You worry about everything, though, in this position, so yeah, you worry about it. I really like the guys. I think we’ve come a long way. We’ll find out on Monday night how far we’ve come. It’s not going to be easy.”