Josh Rosen thought it was a mistake when three quarterbacks went before him in April's draft.

A day after watching Sam Bradford let it rip to begin training camp, the Cardinals' first-round pick has no qualms about sitting No. 2 on the depth chart.

While both quarterbacks are in their first years with the Cardinals, Bradford's NFL experience shined through during a sharp practice session on Saturday. Coach Steve Wilks has anointed Bradford his starter unless he loses the job, and Rosen understands the uphill climb it would take to unseat him.

"I think people forget how good he is," Rosen said. "He's unbelievable. He's just unbelievably quick and decisive with everything he does. The ball just doesn't touch the ground. He's very quick and light on his feet in the pocket. The ball goes where it needs to go. It's his first year in this offense, too, and it seems like it's been his fourth."

Rosen's start to camp was more of a mixed bag, something expected for a rookie still learning his way in the NFL. Coach Steve Wilks liked one of his seam passes enough to highlight it in a team meeting, but said there are times when Rosen's decision-making is an issue.

"We've got to make sure we shore that up," Wilks said. "But for the most part, we can see the arm strength as well as the accuracy."

Rosen took second-team snaps to open training camp, the latest sign that the Cardinals are priming to get him up to speed quickly. (He did get a few first-team reps late in the session as Bradford took a couple plays off.) Rosen said he's still thinking a lot on the field and once that calms down, his talent will begin to shine through.

"Sometimes you're so worried about getting the ball out and not getting sacked, you might put the ball in a sketchy situation," said Rosen, who threw an interception in a seven-on-seven drill on Saturday. "The way I'm going to go about fixing that is mastering the playbook. When you walk up to the huddle (and) the only thing you have to worry about is the defense and not what you're doing, it makes all of your decision-making a lot easier, quicker and more deliberate."

Bradford's skillset has never been his downfall, but his health. While Rosen seems unlikely to wrest away the starting job heading into the season, he pledges to be fully prepared if an injury strikes.

"Football is a very violent sport, particularly over any other sport," Rosen said. "Injury rates are basically at 100 percent throughout a career. Even if (Wilks) said, 'Josh, you're 100 percent the backup,' I'm still going to practice like the starter because I very well could be in there, and vice-versa with whoever is starting."

If the Cardinals didn't have a player with Bradford's talent on the roster, there would be a clearer path for Rosen to play immediately. Even so, Rosen is happy with the arrangement.

"I'm very fortunate that that is the standard I get to see coming into the NFL," Rosen said. "I'm not competing with someone who was a career backup and was maybe getting their shot here. … He's unbelievable, and I'm going to try and top that, whether now, later, whenever. I'm just very fortunate that that's the standard that I get to go see when I step foot in the NFL. He's a really, really good quarterback and I think a lot of people are sleeping on him."