San Francisco 49ers head coach Kyle Shanahan announced quarterback Brock Purdy has entered concussion protocol, per NFL Network's Ian Rapoport.

The announcement comes two days after the 49ers sustained their second consecutive loss when they lost to the Minnesota Vikings 22-17 on Monday Night Football. It's unclear when Purdy started feeling symptoms to enter concussion protocol, but the move will put his status in jeopardy for the Niners' upcoming game versus the Cincinnati Bengals.

After a seemingly perfect 5-0 start to the season, the 49ers have sustained two surprising losses to the Cleveland Browns and Vikings. In the Browns game, Purdy was under constant duress and the offense could barely get going most of the day. Against the Vikings, he threw two uncharacteristic interceptions in the fourth quarter. Overall, Purdy went 21-30 for 272 yards with one touchdown and the two picks as Kirk Cousins out-dueled him.

If Brock Purdy is unable to play versus the Bengals, Sam Darnold will get his first start with the 49ers. Darnold won the backup job over Trey Lance prior to the season. Darnold previously played for the New York Jets and Carolina Panthers, but had little success thanks to injuries and a lack of talent surrounding him.

The 49ers desperately need a win versus Cincinnati to avoid a third straight loss and falling to 5-3. If the 49ers plan to win the NFC West again, they cannot afford to continue slipping. The Bengals are a tough matchup and coming off of two straight wins, but San Francisco will have home-field advantage for this game.