Cardinals cornerback Justin Bethel breaks up a pass to Chiefs wide receiver Jeremy Maclin earlier this preseason.

As a group, the Cardinals' defensive backs are tight knit and you can see it every day on the practice field.

But there may be no one who gets bigger backing than Justin Bethel – one-time small college safety -- in his quest to develop as an NFL cornerback.

"To see how raw he is and the ability he has, the sky is the limit," cornerback Patrick Peterson said. "We just root him on. We want to make sure we are always in his corner and we are giving him the confidence to go out and play with that

swagger."

Confidence is the buzzword surrounding Bethel. Bruce Arians says he sees more of it in Bethel. His teammates want to instill it in Bethel. Of all this, Bethel is acutely aware. Everyone around Bethel has long raved about his athleticism and speed. Those are not at issue.

"I think that sometimes it might come off that I don't believe in my talents, which is not the case," Bethel said, shaking his head with a smile. "I totally believe in myself. I'm just really hard on myself sometimes and it can come off like, 'Oh, he doesn't believe in himself.'

"I believe in what I am doing. I'm just a hard critic of myself, especially knowing how good I can be. I guess I can see how I can come off that way. They think they gotta take care of me, but no. I'm fine."

The Cardinals need Bethel to be better than fine. While the secondary as a whole is solid – and while safety Tyrann Mathieu can fill in as a slot cornerback – the cornerback position itself isn't deep. Peterson and Jerraud Powers will start. Bethel has now earned himself the third spot, Arians said. Beyond that, there are only questions. The fourth cornerback would have to be undrafted Jimmy Legree or Cariel Brooks, perhaps, or maybe a waiver claim.

In any case, Bethel is the main safety net. Already, Bethel has gotten a ton of first-team work – and two preseason starts – with Powers battling oblique and hamstring injuries.  

"That's why I'm trying to be better, so I can be that third corner," Bethel said. "You need one, and I need to step up and be

that guy. I have the abilities and talent to do it. I just want to be accountable so if I do have to come in, my coaches and teammates don't have to worry, thinking, 'Oh he's in, we really have to do coverages to help him out.' I want them to be just as confident with me as they are with J.P."

Arians said Bethel has performed so well that the Cardinals are developing a couple more defensive packages to be able to get him on the field even when Powers his healthy. That was only going to happen with Bethel becoming steady in his play, which Arians has seen.

The confidence, too, has blossomed. Arians believes that might be the most important aspect of the position, regardless of who is playing it.

"You're going to get burned," Arians said. "Can you bounce back the next play? That's the whole thing about playing corner, is having an eraser. You just have to get past the last one, go on to the next one because you're going to get beat sometimes. And there are going to be perfect throws. Justin gets hammered by some perfect throws. You gotta shake that (expletive) off and keep on going."

If the other defensive backs can help with a high-five or backslap after a Bethel pass breakdown in practice, all the better.

"He's definitely stepped up his game as a guy we're going to need and a guy we're going to use," Powers said. "He realizes that."

Bethel, a two-time Pro Bowl selection on special teams, said he doesn't think his special teams work will be diminished even as third cornerback – although if he were to have to start, that could change the equation.

Bethel is also set to be a free agent after the season. He insists he isn't thinking too much about his contract because he doesn't want the distraction. Besides, if he doesn't play well as a cornerback, it hurts him when it comes to a contract anyway.

"It's about getting that confidence in games," Peterson said. "It's different when you are out here practicing and batting down balls. But when it counts, there is a lot more pressure on you, and it's all about seeing how he's able to respond."