49ers QB Brock Purdy clears concussion protocol, will start vs. Bengals

On Wednesday, Kyle Shanahan told reporters, "He started getting symptoms on the plane. So we found that out when we landed. We were all pretty asleep. Then he got all checked up and now he's in the protocol."

When a player enters the NFL's return-to-participation protocol, he is required to pass through a series of five phases in order to be cleared to play. Purdy participated in Wednesday's walk-through and was limited during practice on Thursday, a sign that Purdy was in stage four, and his symptoms were gone. In phase four, a player is allowed to take part in non-contact drills. Purdy was able to fully practice on Friday.

Purdy did not speak with the media on Friday, however. Players in the concussion protocol are not required to do so. Backup quarterback Sam Darnold met with the media instead.

Asked if Purdy would start the game on Sunday if cleared on Saturday, Shanahan said, "Yeah, definitely. He was full go today [Friday], so he's just got to pass that tomorrow." With the 49ers announcing that Purdy has cleared the protocol, expect the see Purdy listed as the starting QB for the team on Sunday.

Wide receiver Deebo Samuel is still listed as out for Sunday. Left tackle Trent Williams is listed as questionable. Last week, Williams was listed as doubtful.