49ers' Brock Purdy in concussion protocol, uncertain vs. Bengals - ESPN

SANTA CLARA, Calif. — Less than 48 hours after their loss to the Minnesota Vikings on Monday night, the San Francisco 49ers had a surprise and significant addition to their injury report: quarterback Brock Purdy.

Coach Kyle Shanahan announced Wednesday afternoon that Purdy is in the NFL's concussion protocol after playing all of Monday night's game, leaving backup Sam Darnold to step in at practice while Purdy recovers. Purdy made it through Monday's game without any apparent issues but began feeling symptoms as the team was traveling back to the Bay Area.

«He started getting symptoms on the plane,» Shanahan said. «We finally found that out when we landed. We were all pretty asleep but then he got all checked up yesterday and now he's in the protocol.»

Shanahan and the Niners were unsure when Purdy suffered the injury in game but Shanahan said there were no obvious signs when communicating with Purdy or in his performance during the game. Purdy didn't take many hits but he did attempt a pair of quarterback sneaks midway through the fourth quarter.

The concussion diagnosis puts Purdy's status for Sunday's game against the Cincinnati Bengals in question. Shanahan said that, by the rules of the concussion protocol, Purdy does have enough time to clear it to be able to go against the Bengals.

It wouldn't be the first time this season the Niners had a player suffer a concussion one week and play the next. Guard Jon Feliciano did it in Weeks 4 and 5, returning to step in for an injured Aaron Banks at left guard against the Dallas Cowboys after dealing with a concussion against the Arizona Cardinals.

But there's a smaller window for Purdy to come back since the Niners played on Monday Night Football and have to play on Sunday.