49ers' Brock Purdy could clear concussion protocol Sat., play Sun. - ESPN

SANTA CLARA, Calif. — San Francisco 49ers quarterback Brock Purdy has not yet cleared concussion protocol, but there is still a realistic chance he will start Sunday against the Cincinnati Bengals.

Purdy went into concussion protocol early Tuesday after feeling symptoms on the team's plane ride home from Minnesota late Monday night. Since then, Purdy has passed four of the league's five steps in the concussion protocol.

That has allowed Purdy to participate in practice on a limited basis Thursday and then be full go in Friday's session. Officially, Purdy is listed as questionable for Sunday, but he will attempt to pass the final step of the protocol on Saturday. If he clears that, he will start, according to coach Kyle Shanahan.

«That's the last thing he's got to do,» Shanahan said. «Just one step left… He was full go today; he's just got to pass that tomorrow.»

The final step of the NFL's concussion protocol requires Purdy to be cleared for full contact by the Niners' team physician and be examined by an independent neurological consultant. If the independent consultant agrees with the team physician that his concussion has resolved, he can play against the Bengals.

Purdy appeared to suffer the injury on a quarterback sneak midway through the fourth quarter of Monday's loss to the Vikings, when he and Minnesota linebacker Jordan Hicks had helmet-to-helmet contact in the pile. Purdy finished the game, throwing two interceptions in the closing moments.

This week, Purdy has progressed through the protocol with a notable step forward each day. In Wednesday's practice, Purdy had to be held out of parts where the team was in helmets, though that session was a walkthrough. On Thursday, Purdy had moved further along in the