Kyle Shanahan: Brock Purdy is in the concussion protocol

It might be Sam Darnold time for the 49ers in San Francisco.Coach Kyle Shanahan told reporters on Wednesday that starting quarterback Brock Purdy is in the concussion protocol. Shanahan said that Purdy started having concussion-related symptoms on the flight home from Minnesota.As explained on Tuesday's PFT Live and mentioned here, Purdy was rocked by a hit from Vikings linebacker Jordan Hicks when attempting a quarterback sneak on third and short in the fourth quarter. The overhead view showed just how violent the contact was.He threw both interceptions to Vikings cornerback Cam Bynum after that moment. However, there was nothing about Purdy's demeanor that suggested he was feeling the effects of a brain injury.Will Purdy be cleared to play on Sunday? Given that the concussion was suffered on late Monday night, it won't be easy to get full clearance. If Purdy isn't cleared, Darnold would get the start against the Bengals on Sunday. If Darnold plays, he would be backed up by former Bengals backup Brandon Allen.The 49ers are on a bye in Week 9. The 49ers play the Jaguars in Jacksonville in Week 10.