At least 10 rookies have been active in every game for the San Francisco 49ers since Week 4. At least 10 rookies have played in every game for the 49ers since the bye week. San Francisco's rookie class has contributed significantly to the team this season. That includes everyone from first-round pick Reuben Foster, who is the 49ers' highest-graded player this season, according to Pro Football Focus, to key contributors like undrafted free agent running back Matt Breida.

Head coach Kyle Shanahan is pleased with the team's rookies and all they have accomplished this season. During a Friday morning interview on KNBR, he discussed the younger players on his roster.

"They've helped us out a ton through this year," Shanahan said on the "Murph & Mac" show. "I think they've gotten better. Even like [Kendrick] Bourne and [Adrian] Colbert, those guys have come a long way. Some of them were helping early in the year. Some came on in the middle, guys like Bourne and stuff, but it's been a huge credit to those guys.

"We threw a number of those guys in some situations that we believe they could do, but they weren't just completely, absolutely ready for. They had to go in there whether it was for injury or whether it was because they just beat out the guy in front of them. They got into some situations where they did some good things early, but it was very up and down and inconsistent.

"It was a credit to those guys because I've seen it both ways. Sometimes you put guys in, you put that pressure on people, and you throw them in some situations that they're not 100-percent ready for, some guys fold. The pressure gets to them, and they get worse as it goes. A credit to our guys.

"I think we've got a special group of people where they've just grinded every week, they've worked throughout the year, they didn't let the record get to them. They just kept working, and they fought through a lot of stuff, and I feel all the guys, especially the ones that you mentioned, I think they're playing the best that they've played all year right now and hopefully that will lead them with some confidence going into the offseason. And you're right; if they go into it thinking that they've arrived and feeling real good about themselves, I promise they'll be worse next year.

"So you better stay humble, you better keep working, and understand what got you to get better throughout the year. If they keep working to get better, then they will be better next year."

You can listen to the entire interview with Shanahan below.