Kyle Shanahan provides final updates ahead of 49ers-Cardinals Week 4 matchup

San Francisco 49ers head coach Kyle Shanahan spoke with reporters after Friday's practice, providing final updates ahead of the team's Week 4 matchup against the Arizona Cardinals. Here is everything he had to say.

Transcript provided by the San Francisco 49ers Communications staff.

Opening comments:

"Injuries for this week: [WR] Jauan Jennings will be doubtful, [WR] Deebo Samuel, questionable, [RB] Elijah Mitchell, questionable, [LB Dre] Greenlaw, questionable, [LB Demetrius] Flannigan-Fowles, questionable. Go ahead."

What is Elijah's injury?

"Tripped up his knee yesterday at the end of practice."

Tripped up his knee?

"His knee, got tripped up and dinged his knee."

With Deebo's knee, is that a sprain or is that a bruise? What is that?

"I'm not sure."

You said Elijah banged his knee. He tripped and then banged his knee?

"Yep."

How has WR Ronnie Bell increased your confidence in him by the way he's played?

"A lot. He started in pre-season, started in practice, carried over to the games. He's been great in these first three weeks. Played really well without the ball and when he's got opportunities, he has done exactly what he's expected to do and gets better in practice every day and been real excited with him so far."

How did WR Brandon Aiyuk go through practices this week?

"He had a real good week. Yeah, he's good to go, off the injury report. Excited to have him back."

Just the style that Deebo Samuel plays, obviously delivers a lot of blows, takes a lot of blows. Does that give you pause about whether he could go given a rib injury?

"No, I think his rib feels good. I think that's not a problem for him. Just had to stay off his legs most of this week to get some of the soreness out of his knee. He was able to go some today for the first time. So that gives him a chance there for Sunday."

A lot gets made of the versatility of RB Christian McCaffrey and Deebo, but how much does what Aiyuk can do for the x position do for your offense?

"A ton. Every guy's so important that we have out there and every guy is a very good player and every guy affects the other player too. So, depending on where they roll the defense, everyone's got matchups and matchup advantages, but Aiyuk can run all the routes that any receiver can. He can play outside, he can play inside, he can play like a fast, quick guy and he can play like a long, big guy. Aiyuk is a very versatile player."

You haven't faced too many runs defensively. You have these guys coming in and the Cowboys and the Browns, so it's a good stretch here. What's your confidence level on the run defense right now?

"It's been good so far, but you're right. I don't think we've been challenged a ton in it. I think our biggest challenge will be this week and just what you mentioned going ahead, I think it'll only get stronger. So, we've got our work cut out for us, we're well aware of that. They've been committing to it, they've been blocking it well, and the runner has been running hard and they got a quarterback element that always makes it a problem. So we've got to be on our stuff this week."

What's the exchanges been like with QB Brock Purdy as he's developed since last year, this year, like during the week and during the game? Is he more assertive with you or does he still sit back and listen or how would you describe the way your interaction is?

"Almost the same as it's always been. Brock processes everything. Every time you talk to him he sits and listens for a while. You can see him think, you can see him try to understand everything and then he always talks if he's got questions. But in the games, he more processes stuff. If he sees something different, he will tell you right away. But, Brock's one of the easier players I've been around to talk to and there's zero layers there."

Does he say like, 'Look, I think this'll work.' Or doe he leave that to you?

"Most people leave that to the coach. Usually players aren't out there thinking about all that stuff. Usually they're out there thinking about their job and stuff. There's more stuff that goes on the quarterback's plate than any line of work that I've ever been around. So the stuff that they got to control and everything, it's very rare that they're thinking of blocking schemes and route combinations and coverages, but they know what the plan is throughout the week, they know what they feel on stuff, I know what they feel on stuff. As the game unfolds, we all know what we're expecting and the conversations are usually what's gone differently. And then it's, 'Hey, are we going to that play that's different because we said they might do this and I know what you're thinking, you still want to go to that?' Stuff like that. That's usually relayed to [quarterbacks coach Brian] Griese and stuff, who's sitting there, going over pictures with them on the bench. A lot of stuff's relayed back when I'm out there by the white."

What other lines of work have you been in besides football?

"I was a ball boy for the Niners in '94. I guess that's football, but that's in the equipment world. And that's it, that I've seen. I'm even throwing other sports in there, but I haven't coached any. So I'm just taking a wild guess. But a quarterback's got a lot on his plate."

Will you have to elevate a receiver or two? And then who would be in line?

"It'll be [WR] Chris [Conley] or [WR] Willie [Snead IV]. Both of those guys are the same guys in subtly different ways to us, but we've got a lot of confidence in both of them. We'll figure that out based on which guys are down."

You wouldn't have both of those guys up?

"We could, yep. Only allowed two guys up, so it plays into everything though, so we'll see how it goes with the guys that are questionable."