How Short is Brock Purdy's Leash with the 49ers?

Brock Purdy is quite a good quarterback, and Kyle Shanahan is an extremely fickle head coach. Both statements are true.

Purdy has lost just one game as a starter that he finished. That's an incredible start to a career for any quarterback. And yet, he was bad in Sunday's loss to the Browns. He threw an interception. Missed a wide open touchdown pass to Christian McCaffrey. Posted a passer rating of 55.3.

Purdy was one of the main reasons the 49ers lost a game they should have won.

Most reasonable people would conclude Purdy merely had a bad game against a great defense -- every good quarterback has a bad game eventually. No one is immune to adversity. Give Purdy some grace and allow him to bounce back.

Can you imagine Kyle Shanahan saying any of that?

He might say it publicly, but privately we know he's extremely impatient with his quarterbacks. He moved on from Trey Lance after just four starts and soured on Jimmy Garoppolo after eight. Once Shanahan changes his mind about a quarterback, that's it.

And remember, Shanahan didn't discover Purdy -- the scouting department did. So he isn't tied down to Purdy. He can take credit for Purdy's improbable success while it lasts, but if it starts to disappear, Shanahan can always pivot to the quarterback he handpicked this offseason -- Sam Darnold. Remember, Shanahan compared Darnold to Steve Young just a few months ago. No one believes in Darnold more than Shanahan.

So if Purdy has another bad game this week against the Vikings -- unlikely -- don't be surprised if we see Sam Darnold sooner rather than later.

You know Shanahan can't help himself.