Sam Darnold beat out Trey Lance to win the San Francisco 49ers' backup job in training camp, and now he looks likely to get the chance to start against the Cincinnati Bengals after Kyle Shanahan revealed Brock Purdy is in the concussion protocol.

Purdy, Shanahan said, began showing concussion symptoms on the flight back from the 49ers' 22-17 upset loss at the hands of the Minnesota Vikings.

"He started getting symptoms on the plane, I found that out when we landed. He got all checked up yesterday and now he’s in the protocol," said Shanahan. "He does have enough time [to clear the protocol], he’s just got to go through the process.

It was a game in which Purdy threw interceptions on each of the Niners' final two drives when San Francisco had a chance to take the lead.

The defeat dropped the 49ers to 5-2 and now Darnold looks set to be tasked with ensuring a blip does not turn into a three-game losing streak. No player in the concussion protocol this season has played in the same week.

A pairing of Shanahan and Darnold has long seemed like an intriguing one. The third overall pick of the 2018 draft possesses tremendous natural talent as a thrower but has arguably never had the chance to play for a coach who can put him in positions to succeed.

Shanahan can do just that and, if Purdy cannot go, he will need to do so against a tough Bengals defense in the 49ers' final game before their Week 9 bye.

49ers’ Brandon Aiyuk is the most open receiver in the NFL

Nobody can match him this season.