SANTA CLARA, Calif. (AP)San Francisco 49ers quarterback Brock Purdy was a full participant in practice Friday and could be cleared from his concussion to play this weekend against Cincinnati.

Coach Kyle Shanahan said Purdy still must clear a final step on Saturday in order to play Sunday against the Bengals. He is listed as questionable.

Purdy got hit in the helmet late in Monday night’s loss at Minnesota. He reported concussion symptoms on the flight home and was placed into the protocol.

Purdy was able to take part in a portion of a walkthrough Wednesday, was limited in practice the next day and was a full participant Friday. Shanahan said Purdy will start if he clears the protocol, otherwise Sam Darnold will get the nod.

In other injury news, left tackle Trent Williams returned to practice on a limited basis and is also questionable to play Sunday with an ankle injury that sidelined him last week.

“Better than last week,” Shanahan said of Williams’ status. “I’m still not sure. He’s got to improve here in the next 48 hours. He can go up to kickoff though.”