The San Francisco 49ers quarterback struggled to move the offense for much of the game. Gone were the aggressive downfield passes we saw the previous two weeks, but this had everything to do with a well-coachedRams defense.

"I've played better. There were plays out there I should have made," said Kaepernick, who summed up the defeat in one word: "Frustrating."

The Rams enjoyed excellent play from their front seven and, especially, their cornerbacks, something Kaepernick acknowledged. The second-year pro talked about aRams defense that was prepared for everything the 49ers tried to do.

It wasn't an easy afternoon for Kaepernick. His darkest moment came on a botched fourth-quarter pitch to wide receiver Ted Ginn deep in 49ers territory. Rams cornerbackJanoris Jenkins recovered the fumble from two yards out and scored a game-altering touchdown.

"That was just a bad pitch on my part," said Kaepernick, who finished with 208 passing yards and another 84 yards on the ground. He certainly will hear whispers about how a tested veteran like Alex Smith would have responded down the stretch.

Those whispers are foolish. Harbaugh isn't about to dial it back to Smith.

"I'll let you know if there's a change, but right now, I think it'll be the same as it was this week," Harbaugh said, via The Associated Press. "I'm proud of Kap, proud of the way he played."

The switch to Kaepernick has been in the works for months. Harbaugh tutors quarterbacks as well as any coach in the NFL and understands what both of his passers offer. Kaepernick can make throws Smith cannot. He is willing to put the ball where Smith won't. Kaepernick's mobility is only part of the equation, and Harbaugh thought carefully -- and patiently -- about making the change.

Kaepernick's tremendous upside isn't negated by one tight loss to the Rams. The 49ershave made a decision at quarterback -- and they're sticking with it.