Steve Keim knows the Josh Rosen conversations are already happening within the fan base.

"That's the popular question around any water cooler," the Cardinals general manager said Friday morning. "When does the backup quarterback play?"

For Keim, though, there is not a simple answer, which he explained during his segment during the "Doug and Wolf" show on 98.7, Arizona's Sports Station. Coach Steve Wilks said repeatedly this week -- while reiterating Sam Bradford is the starting quarterback "right now" -- that the myriad offensive problems of the Cardinals don't just fall on the quarterback's shoulders.

Keim echoed those sentiments, bringing up the need for better protection in the passing game, the need to run the ball more effectively, and the need to get more consistency from the wide receiving corps.

But the Rosen questions will persist, magnified this week after No. 1 overall pick Baker Mayfield came into the game Thursday night and rallied the Browns to a win over the Jets. Of the four top 10 quarterbacks taken, Rosen is now the only one to have yet appeared in a game.

"It's a tough question," Keim said. "When the time is right, Josh will have his opportunity.

"At the same time, you never know how a guy is going to be affected. Some guys have played too early and it has crippled their career. I'm not going to name names, but I think a lot of us can think of certain players. Then there are guys who have come in and had success right away. But usually it's a rocky road."

Keim noted that greats like Troy Aikman and Peyton Manning had brutal rookie seasons before rallying. He pointed out that burgeoning Chiefs star Patrick Mahomes basically sat as a rookie before having his fantastic start to this season.

"I don't think there is any exact science to that," Keim said. "But I think there is certainly a feeling of knowing when the time is right."

Offensive coordinator Mike McCoy was asked about Rosen's readiness if he had to come in. McCoy simply said Rosen was ready just like every other player on the roster. But Keim said Rosen continues to look good in practice and that he has shown intellectually he can handle the job.

Keim acknowledged that, if he had a choice, he'd rather that Rosen be given a week of practice as a starter and get under center from the beginning of a game rather than be brought in at halftime or the middle of a game. Then again, as a backup, that might be something he'd have to do if Bradford got hurt.

"He's got to be ready regardless," Keim said.

With the Cardinals 0-2 and coming off a rough pair of blowouts, Keim talked about improvements needed on defense as well, and noted that he has taken the start personally.

"I take a lot of pride in, not only this organization but what I need to do," Keim said. "There's no other way to look at it other than to look at yourself and wonder why are things going wrong. You look at the talent and think it's at a certain level that we should be able to win, but at the same time you have to understand the team concept and all the things that play into it.

"I'm the first one to look at myself in the mirror. I'm extremely frustrated right now."

Maybe, it was suggested, Rosen would be the jolt the team needs to get out of its doldrums.

"I don't think it's a secret it needs something," Keim said. "More than anything, it needs some balance. We need to run the ball better. We need to protect better. We need to run crisper routes. We need to get more separation.