Quarterback Brock Purdy has entered the NFL's concussion protocol, 49ers coach Kyle Shanahan told reporters after practice Wednesday in Santa Clara.
Shanahan said Purdy first began feeling concussion symptoms on the 49ers' return flight from Minnesota after their loss to the Vikings on Monday night.
Shanahan isn't sure when Purdy might have sustained the concussion because he didn't report symptoms right away, but the 49ers' second-year signal-caller took a vicious blow to the head on a quarterback-sneak in the fourth quarter against the Vikings.
Stay in the game with the latest updates on your beloved Bay Area and California sports teams! Sign up here for our All Access Daily newsletter.
Purdy's two late-game interceptions came after the hit -- one on the play directly after, and the game-ending pick on the 49ers' next possession.
While the 49ers are on a short week ahead of their Week 8 matchup against the Cincinnati Bengals on Sunday at Levi's Stadium, Purdy does have enough time to clear concussion protocol, per Shanahan.
While it's rare for players to play in a game immediately after being placed in concussion protocol, 49ers offensive lineman Jon Feliciano was ruled out during San Francisco's Week 4 game against the Arizona Cardinals and was placed in concussion protocol before being cleared and playing in Week 5 against the Dallas Cowboys.
San Francisco 49ers
Backup quarterback Sam Darnold would be in line to start against the Bengals if Purdy is unable to play Sunday.
The 49ers will hold a walk-through Wednesday, and Purdy is allowed to participate in that portion of preparations for Sunday.
Purdy is coming off the first two regular-season losses of his NFL career after winning his first 10 games.
In addition to Purdy, wide receiver Deebo Samuel (shoulder) and left tackle Trent Williams (ankle) also didn't participate in Wednesday's practice.