Brian Kelly makes his debut as Notre Dame coach Saturday as Irish face Big Ten's Purdue

Brian Kelly set the rules early for his players: No earrings or ball caps, organize your lockers, keep your helmets on and pay attention to detail during practices that won't last more than 2½ hours.

And then there was one more really important decree from Notre Dame's new football coach — don't even think about hitting quarterback Dayne Crist.

Crist, who had knee surgery last November, has been an untouchable through spring and preseason drills.

That will all change Saturday when Kelly makes his Notre Dame debut and Crist his first start as the Irish face Purdue in the season opener for both teams.

"He's going to get tackled. He's going to get hit. He's going to have to run around," Kelly said.

Kelly will be on the sidelines for the first time since Cincinnati capped a 12-0 regular season by beating Pittsburgh 45-44 last Dec. 5, less than a week before he was announced as Charlie Weis' replacement.

And Crist, a little-used backup a year ago to Jimmy Clausen, will be playing for the first time since last Oct. 31 when was hurt in a game against Washington State. He led two touchdowns drives against Purdue last season while stepping in for a sore-toed Clausen.

"Dayne Crist is a guy who is going to have to use all of his tools. He's a pretty good athlete," Kelly said. "But we're not going to put him in a position where we get running hits on our quarterback. That's just not smart."

After appearing in just four games last season and completing 10 of 20 passes, Crist is now being counted on to run Kelly's rapid-paced spread offense, stay healthy and be the centerpiece of the new coaching staff's stated goal — win right away.

"It's a moment that I've waited for for a very long time," Crist said.

Kelly said his last-minute advice to Crist before the game will be simple.

"You don't have to win the Heisman today. Take what they give you, be patient and let the offense come to you. You don't have to force it," Kelly said.

Crist said he wasn't sure what Kelly's pre-game approach would be, whether he'd have a big motivational speech or just reinforce what he's been trying to get across the last nine months. And that's realize you're playing for a place with a great tradition.

"It will be as much an emotional time for him and the rest of the coaching staff as it is for us being their first game in Notre Dame stadium and everything like that," Crist said. "Coaches always know the message that they want to relate to their team, and coach Kelly is good at communicating a clear message. I don't think Saturday will be any different."

Keeping Crist off the ground Saturday will mean blocking one of the nation's best defensive ends in Ryan Kerrigan, who led the Big Ten in sacks last season with 13.

And if Saturday's game is a new start for Kelly and a defining moment for Crist, it's also a chance at renewal for Boilermaker quarterback Robert Marve, who transferred from Miami. Dealing with the din at Notre Dame Stadium shouldn't be a big deal since Marve's first collegiate start came against Florida at the Swamp in 2008.

"I'm looking forward to showing everybody what I've got," Marve said.

Just as Crist will be able to rely on junior wide receiver Michael Floyd, Marve can depend on Keith Smith, who caught 91 balls for 1,100 yards last season.

Purdue coach Danny Hope is confident Marve will be effective, even though he sat out a season after transferring. And like Crist, Marve has recovered from a knee injury. But he also has more experience than his Notre Dame counterpart: He made 11 consecutive starts for the Hurricanes two years ago.

"He has played in some big games," Hope said.

"There's some things he does very well. If we take care of Robert, if we have enough skill people on the perimeter for him to get the ball to, we have a chance to win, win against anybody. We'll go as our quarterback goes. That happens a lot. The opponent is in the same boat."