Presuming Jim Harbaugh was not hidden behind Kaepernick like a ventriloquist with a hand up his jersey, the coach must have been pleased with his student’s performance. It was straight from Harbaugh’s public relations playbook.

Kaepernick is Harbaugh’s quarterback, molded in Harbaugh’s stony persona. He was drafted for the purpose of eventually leading Harbaugh’s team and was promoted in November to carry Harbaugh’s immediate championship aspirations.

So the attention in these playoffs is on Kaepernick. But it is the man behind him, working the controls, who has the most at stake.

Harbaugh is perched at a peculiar turning point in his coaching career. He is popular in the Bay Area because he has won, not because he is liked, relying on victories instead of personality to build good will. Now, because of the midseason switch to Kaepernick, and the rising expectations caused by his own success, Harbaugh’s popularity promises to be tested as never before.

“Two things sustain you as a coach,” said the former quarterback Trent Dilfer, an ESPN analyst who lives in the Bay Area. “Winning, No. 1. Likability, No. 2. Very few coaches have both. Jim does not have the consciousness of the public perception of him to have sustainability unless he wins. That’s just a fact. He has to win.”