Brock Purdy has cleared the concussion protocol and will start Sunday

Kyle’s update, October 28, 11:00 a.m PT: Good news - Brock Purdy has cleared the concussion protocol. He’ll start Sunday against the Bengals. You’ll have to put those Sam Darnold jerseys away for another week.

Kyle’s update, 3:00 p.m. PT: Here’s a look at the official injury report:

OUT:

Deebo Samuel

Questionable:

Trent Williams

Brock Purdy

Shanahan said that Purdy was full-go, and just needs to pass the final step of the concussion protocol to be cleared.

Shanahan said the team will find out on Saturday whether Purdy is cleared. Purdy could only do walkthrough on Thursday, so he missed a couple of periods. But there were no restrictions for Purdy during Friday’s practice.

Shanahan said that Williams practiced during the early portion where you’re not going against another player, but did not participate during the team part of practice. Shanahan said Williams is doing “better than last week. He’s gotta improve here in the next 48 hours. He can go until kickoff.”

Deebo Samuel is conditioning and doing well. Shanahan said, “hopefully he’ll be ready after the bye week.”

49ers quarterback Brock Purdy threw and participated in his second straight practice on Friday.

That looks like a player who is waiting for the doctors to clear him. Barring no setbacks, the 49ers should have their starting quarterback on Sunday against the Bengals.

Trent Williams didn’t practice, which shouldn’t come as a huge surprise. Williams doesn’t need to practice to play. He’ll likely continue to get treatment up until the last minute before testing the effectiveness of his ankle.

That was 49ers general manager John Lynch’s sentiment Friday morning on KNBR:

“Trent’s progressing well. Trent is a competitor of all competitors. And he had that ankle and was really gearing towards playing last week. He just couldn’t get there. He’s not practiced this week. So I think today is going to be a big day. We don’t do a ton on Friday, but it’s going to be a big day in terms of feeling like, okay, I’m feeling better. I think I can do this.

And Trent’s the type of player you wait right up until Sunday if you have to. I guess it does give you some confidence that Trent’s a seasoned player. You trust his point of view, once the doctors clear him, as to whether he can go, and then knowing he’s got some time to heal up after because of the bye week. If Trent can play, he’ll play. And today and the next couple of days will be big in terms of continuing the healing process, so he can go function.”