It was their first series in an NFL regular-season game, and two Carolina Panthers rookies had yet to get comfortable.

Linebacker and first-round pick Luke Kuechly was trying to make every play on the opening drive Sunday against the Tampa Bay Buccaneers, putting him out of position.

“I was playing too fast,” Kuechly said. “I wasn’t where I needed to be on a couple of plays. One person breaks down on defense, and the whole defense breaks down.”

Rookie cornerback Josh Norman also made a mistake, on a third-down play from the Panthers’ 24 that set up a touchdown.

That play was still was on his mind Monday, when he told reporters that if he had been inside the receiver instead of outside he could have gotten a pass breakup, if not an interception.

Instead, the play went for a first down, helping the Bucs complete an 80-yard touchdown drive in a 16-10 Tampa Bay victory.

“The preseason games … we got them in, and we felt comfortable,” Norman said. “Then the first official game, we went out there and did some good and bad things.”

Panthers defensive coordinator Sean McDermott understood.

“A lot of young guys in that first drive got their first exposure to regular season NFL football,” he said. “We showed some our youth there.

“What was nice to see though was how those young guys settled down, in the second half in particular, and played good solid Panther style defense.”

Norman and Kuechly were among five Carolina rookies who played Sunday.

Here’s how the others did:

•  Rookie defensive end Frank Alexander made an impact, batting down a Josh Freeman pass on third and 11 and forcing a field goal, then getting his hand on another pass on Tampa’s next possession. “I was nervous coming out, but once you get that first play under way and you see what the tempo of the game is and you make that adjustment,” he said.

•  Rookie returner Joe Adams returned one punt for 21 yards, longer than the Panthers’ best punt return of 2011. He had a kickoff return of 31 yards, which would have tied for third.

•  Guard Amini Silatolu, the offense’s only rookie starter, struggled the most. Transitioning from a college offensive tackle, he was penalized twice, for a false start and a critical holding penalty on third and 2. “He’s physical. He’s learning,” offensive coordinator Rob Chudzinski said. “This group gave him a lot of different looks and games he had to pass off. So he’s going to keep getting better and learning … He’s got a bright future, and he’s going to be a heck of a player.”