GLENDALE, Ariz. -- Anyone looking for Arizona first-round draft pick Robert Nkemdiche last season barely got a glimpse of him.
Between injuries and a need to mature as a professional, the 6-foot-4, 296-pound defensive tackle wasn't on the field much.
The rookie appeared in five games and made just three tackles.
Nkemdiche is not alone among first-round picks who have had to sit a lot in their first season. D.J. Humphries didn't play a down for the Cardinals in the 2015 season. Now he's the starting left tackle.
"That's the nature of the draft now," coach Bruce Arians said. "It's not 15 years ago where you plug and play a first-round pick. These guys need a ton of work to learn to become professionals. That doesn't mean if they don't play as a rookie they're busts. It means we're grooming them to probably take somebody's place and they're ready to go."
Nkemdiche could help fill a big hole left by the departure of Calais Campbell, the towering defensive lineman who signed a lucrative free agent contract with the Jacksonville Jaguars.
They are different physically, for sure. Nkemdiche's body is more reminiscent of Darnell Dockett's. And Nkemdiche doesn't like to compare himself to anyone anyway.
"I'm not really going to replace Calais," Nkemdiche said. "It's going to be the best me and see what happens."
The Cardinals expect Nkemdiche to join Josh Mauro, Corey Peters and Frostee Rucker in the rotation in Arizona's three-man front.
"He's been very disruptive," Arians said, "and we look for him to -- knock on wood -- stay healthy and have a very solid year."
A second-team All-American out of Mississippi, Nkemdiche has the body and skills that any pro scout would love. But he was arrested after he fell out of a hotel window in Atlanta in December 2015. Marijuana was found in the hotel room.
Nkemdiche took responsibility and insisted the incident did not reflect his true character.
Still, he slid all the way to the Cardinals at No. 29 overall last year.
There are no such concerns now.
Asked before Friday's practice how Nkemdiche's off-the-field behavior has been since he came to Arizona, Arians said, "It's been fantastic, fantastic."
That adjective often fits Nkemdiche's play this training camp, too, but he's taking a low-key approach to what promises to be a much higher profile role.
"Just taking it day by day honestly, man, and trying to focus on the fundamentals that I'm being taught by my coach," he said, "and trying to work on my craft and get better, just taking it moment to moment."
He called his rookie year "a learning lesson."
"It was for me just to see how the ropes go as an NFL pro," Nkemdiche said, "and take it all in so I can keep getting better and working towards my goal as a pro.'"
One of the themes of this camp, as the Cardinals look to bounce back from a disappointing 7-8-1 season, is to concentrate on the little things. Nkemdiche said that's exactly what he's doing.
"They're looking for the best Robert," he said, "little details and just do my job and be the best me that I can be."
Nkemdiche still has to think too much rather than automatically know what he is to do on any given play.
"For me it's really understanding plays and not being hesitant with what I want to do," he said. "It's a lot better when you can play with understanding what you have to do and how the defense actually works, because football's a game of inches and one inch can make you behind the play."
And he fits right into the Cardinals' attacking style.
"This is what I like doing," he said. "I like going for it. I like being aggressive, vertical, as long as I understand that my hands and technique matters and where I'm supposed to be matters and things like that."
Nkemdiche is still very young. He won't turn 23 until Sept. 19.
"My confidence is always sky high just because I know who I am," he said. "I have so much belief in myself and I know what limit I can reach. My confidence is always at a prime. I just want to keep that and keep getting better as a player and a person and keep being a pro."