TEMPE, Ariz. -- There's someone in the Arizona Cardinals locker room who understands what rookie cornerback Brandon Williams is going through this season in transitioning from college running back to NFL corner.

That's fellow corner Marcus Cooper.

Cooper transitioned from wide receiver to cornerback during his junior season at Rutgers at the urging of his coach. It led to him getting drafted in 2013. He was traded to the Cardinals just before the season and stole Williams' starting job a week later.

Cooper's experience as a wide receiver has been to his benefit in the NFL. He understands route combination and route trees. It's helped him figure out -- preemptively -- what routes receivers will be running before the snap.

"I try to look and see what things I would do to get open if I was the receiver and just figure out what to do to stop how I would get open and go from there," Cooper said.

Cooper cited his wide receiver background as a reason behind the first of his two interceptions in Week 2 against Tampa Bay.

"I just put myself in the No. 3 spot and I think of a route concept and how I would run that route and that's what I just took, what I would've thought I would've did and just ran with it, and was able to make a play with it," he said.

Cooper's transition from offense in college to starting cornerback is a blueprint of sorts for Williams, who started the first game this season. He started Week 2 but was replaced by Cooper in the second quarter, as they were supposed to alternate playing time. But Cooper had an interception on his second defensive play with the Cards and has kept the job ever since.

Even though Cooper had rough last two seasons in Kansas City, which ultimately led to his departure from the Chiefs, he's found a rebirth with the Cardinals. That might be a lesson in the future for Williams.

At the moment, however, he's been trying to pick Cooper's brain about transitioning from offense in college to defense in the NFL.

"I watch him like I watch Pat [Peterson]," Williams said. "See how they react to different situations and what not, technique and stuff like that."

While Williams has become an apprentice under Peterson, a five-time Pro Bowler, he stands to gain as much from studying Cooper. Coach Bruce Arians thinks Williams can learn from Cooper by "just watching."

"Watch how he works," Arians said. "They're very similar. We think the world of Brandon and he's going to be a heck of player. Watch how he works. Ask him question. Brandon's very good about asking Pat, asking all the guys, 'What should I do in my preparation? How do I get to where I want to get to?'"

Cooper has told Williams that getting comfortable at cornerback and understanding the position "took him a while." Williams laughed when he talked about Cooper having an advantage in his transition because he was a receiver, allowing him to get in their heads easier than Williams.

Hearing about Cooper's transition helped Williams understand the road ahead of him.

"It gave me, I guess, more patience over the process to understand it's going to take time," Williams said. "Eventually, if I keep studying and working, I'm going to get it."