SANTA CLARA — It’s Year 3 for Brock Purdy in the NFL and Kyle Shanahan still won’t take the training wheels off the offense for him.

Most NFL quarterbacks have the autonomy to call audibles at the line of scrimmage, especially veteran, cerebral quarterbacks such as Purdy.

And yet, on 3rd and 1 in the first quarter this past Sunday against the Chiefs, Purdy walked to the line of scrimmage and saw that Kansas City had nine defenders in the box selling out to stop the run. Instead of calling an audible and passing the ball as most other NFL quarterbacks would do, Purdy simply handed off to Jordan Mason who gained no yards, and then the 49ers punted.

Why didn’t Purdy audible?

“Usually, we just have an answer built into the play,” Purdy explained. “And so, if we do have like an all-out blitz or something, we usually have an answer of where I should be hitting or where I should be going. And there’s very rare occasions where we walk up to line and we get a look and it’s, ‘Oh shoot, they got us.’ And then I’m supposed to randomly make up an audible. There’s nothing like that. We usually always have an answer for pressures, all-out blitz and things like that. So that’s on me to get to the right guy.”

TRANSLATION: No, Purdy is not allowed to “randomly make up an audible” at the line of scrimmage. Shanahan’s incredible plays are supposed to have answers for everything the defense can throw at the 49ers. Except for when Shanahan doesn’t have the answers, and all Purdy can do is think, “Oh shoot, they got us,” and run a play that’s doomed from the start.

Time for Shanahan to hand the reins to Purdy.