San Francisco 49ers head coach Kyle Shanahan spoke with reporters after Friday's practice as the team prepares for its Week 13 matchup against the Baltimore Ravens. Here is everything he had to say.

Transcript provided by the San Francisco 49ers Communications staff.

Opening comments:

"Thanks for coming guys. Injuries for today, guys who are questionable will be [RB Matt] Breida and [T Joe] Staley. Guys who are out are [DL] Dee Ford and [WR Dante] Pettis."

With Ford out, you've had some attrition on the defensive line the last few weeks. What are your thoughts on just the depth of that unit and obviously came into the year with a lot of guys?

"I still feel good with our depth. Bringing [DL] Jeremiah [Valoaga] off the practice squad, he's been with us all year and in training camp, so he'll step up and do his role. We had a lot of depth going in there and we also have guys who are pretty versatile with how they can play inside and outside in a pinch."

How has WR Richie James Jr. done as his own version of Baltimore Ravens QB Lamar Jackson?

"He's done a real good job. He's given us a lot of ideas just watching him because he's looked pretty good at it. Definitely enjoyed watching him throw, too. I didn't know he's a lefty and he threw it pretty good this week."

You guys were obviously very high on DL Nick Bosa from the start, but why do you think he's been able to make such a quick transition and not have that learning curve that a lot of rookies have?

"Just watching him in college, he was as technically sound and seemed developed at his position as any college player I'd seen. We used to joke about it, but it looked like his dad was taking him through pass rush drills at three and doing cone drills and things like that because he just was so efficient with his hands and his steps. I think a lot of guys in college just went off pure ability and then you get to the NFL and that might work the first time a tackle sees you, but then they adjust and you've got to learn how to rush a lot smarter and more efficiently. Bosa has some freakish ability, but he also has that skillset that he's been working on his whole life."

Beyond the technique, do you think there's a personality component when you have that lineage in the NFL that you're not overwhelmed by the stage?

"Yeah, definitely. I don't know if it's the lineage, I'm sure that helps, but I think he knows he was going to be here his whole life and he knows he belongs. I just think it's true confidence and I think that's why you guys see him the same way every single day."

What happened with Pettis?

"He's sprained his knee. Was it Wednesday or Thursday? Wednesday. Just a non-contact drill. Him and a couple players got tangled up and just sprained his knee. He'll be week-to-week with that."

MCL sprain?

"I'm not sure."

Richie's primary job is returning and in terms of guys who are regular returners, probably has one of the lowest fair catch rates. Is that something that you guys have prodded him to do this year? Kind of be more aggressive while still being careful and not fumbling, but also trying to take advantage as often as possible?

"I think it's just a coincidence. I mean, Richie is aggressive, but we've coached it all the same regardless of who's back there. We haven't changed that throughout the year. Richie's done a good job, they've done well for him. Richie's helped us out on special teams and on offense this year. He's played a number of spots for us and I've been glad to have him."