Cardinals rookie defensive tackle Robert Nkemdiche (right) gets words of advice from veteran defensive tackle Calais Campbell on Sunday.

Coach Bruce Arians likes to bring along rookies slowly, but that's not always possible, and the down side of too much, too soon popped up in the season opener.

Cornerback Brandon Williams, defensive tackle Robert Nkemdiche and long snapper Kameron Canaday were each thrust into important spots in Sunday's 23-21 loss to the Patriots, and it didn't turn out well.

Williams allowed a 37-yard touchdown on New England's opening drive when he played the wrong coverage, Nkemdiche jumped offside on a third-and-9 in the first quarter and Canaday had a low snap on a missed go-ahead field goal attempt late.

The trio could be counted on in key spots again on Sunday against the Buccaneers, but Arians hasn't tried to lift their spirits.

"They're professionals," Arians said. "This isn't high school or college. You get out there and you play. If you make a mistake, you own up to it, correct it and go on."

Nkemdiche said he was really anxious to get a good pass-rush before his penalty and took it as a learning experience.

"It's got to be controlled anger," Nkemdiche said. "I've still got to be aggressive, but I can't be too aggressive. I've got to have good balance. You start feeling it out. The more I keep getting comfortable as a rookie, the more I'll grow as a player."

The Cardinals have traded for a cornerback (Marcus Cooper) and now picked one up on waivers (Tharold Simon) in the past few weeks. Williams knows more playing time is there only if he earns it.

"I approached it like that in camp," Williams said. "I don't have time to have a learning curve if I, in some type of way, want to have an impact on this team. That's the way I go about everything. The obvious is that I just started playing the position and I'm going to have those rough patches, but I don't use that as an excuse."

MATHIEU "DOESN'T NECESSARILY LIKE" CENTER FIELD ROLE

Safety Tyrann Mathieu often plays close to the line scrimmage when fully healthy, guarding wide receivers in the slot, blitzing off the edge and otherwise making use of his talents.

He played primarily a deep center field role against the Patriots in his first game back from his torn ACL on Sunday.

"I don't necessarily like it, but I'm still trying to get back in a rhythm," Mathieu said. "It's a new challenge for me. I just try to embrace and accept it."

Mathieu said he hopes to return to his previous role in the next couple of weeks as his knee gets stronger and he becomes more dynamic. Mathieu played every defensive snap against New England and had seven tackles and a tackle for loss but didn't think he was back to peak form.

"I'm still growing, I'm still trying to get better," Mathieu said. "I didn't feel like I was really in position to make any impact plays. I felt like they kept most of our playmakers out of the football game. They were really prepared for us."

KOETTER REFLECTS ON TIME AT ARIZONA STATE

Buccaneers coach Dirk Koetter spent six up-and-down years coaching Arizona State in the early 2000s. When asked of his memories from that tenure, his first word was "distant."

"I mean, it's been 10 years," Koetter said. "Obviously everywhere you work you come across some awesome people. You have a lot of appreciation for the players, the coaches, the people that worked with us there. Ultimately, under my regime we weren't able to get it done. That was 10 years ago, and now is a different time."

During his stint with the Sun Devils, Koetter had more than a half-dozen framed jerseys of former ASU stars hanging in his office. When he was fired, Koetter gave away all but one to boosters.

He held on to his framed Pat Tillman jersey, and it currently adorns his office in Tampa Bay.

"It just means something special to me," Koetter said. "I didn't know Pat well. I knew him a just a little tiny bit. I got to know his family -- his wife, his father, (his brother-in-law) Alex Garwood -- after the fact. I read the books and the accounts, all that kind of stuff. Pat Tillman's an American hero and it means something to me. I'll always have it in my office."

MATHIS MISSES PRACTICE

Guard Evan Mathis (foot) didn't practice Wednesday and Arians will have a better idea of his game availability after Thursday's practice. Linebacker Kareem Martin (knee), defensive tackle Frostee Rucker (knee) and wide receiver J.J. Nelson (shoulder) also sat out, although Martin is "getting close" to a return, Arians said.

Wide receiver Larry Fitzgerald (knee) and running back Stepfan Taylor (knee) were limited.

The only played limited in practice for Tampa Bay was linebacker Adarius Glanton (knee).