Colin Kaepernick will not start on Sunday against the Atlanta Falcons.

Blaine Gabbert will be under center.

Greg Cosell, Senior Producer at NFL Films, believes the 49ers are making the right decision.

"Kaepernick is so mentally locked up, and all the rest doesn't matter when you're mentally locked up, he just couldn't play," Cosell explained on KNBR 680-AM Wednesday morning. "So he would drop back and he really would have no idea where to go with the football...

"They had no choice in this matter. You can't put Colin Kaepernick out there right now because he's so mentally locked up."

[REWIND: Cosell: Kap's ability to 'run fast in a straight line' doesn't matter]

Through eight games, Kaepernick has completed 144 of 243 passes (59.3 percent) for 1,615 yards. He's thrown six touchdowns against five interceptions.

His 78.8 passer rating is 28th out of 33 qualified quarterbacks.

The 49ers are averaging a league-low 13.6 points per game, to go along with a league-worst 282.3 yards per game.

Is it possible that San Francisco's coaching staff isn't utilizing Kaepernick's skillset?

"For those who believe that the 49ers were not using him properly, I would disagree with that totally," Cosell said. "Look at the first seven or eight plays of the game this past week. What they did was, they did boot-action, play-action boot, which defines a read and gives you an easy throw. They did read-option. But then it got to be 3rd and 3 and they wanted to throw the ball with a drop-back pass game, which is standard operating procedure in the NFL. You have to do that somewhere in the NFL.

 

"And this a perfect example of being locked up -- he had Vernon Davis running the crosser versus McDonald, wide open, right in his field of vision. He did not see that, or it did not register and instead he threw it to Patton who was really well-covered on the shallow cross. It was another example of a big-play opportunity missed because he just didn't see it."

Additionally, Kaepernick acknowledged that he missed a wide open Torrey Smith at the line of scrimmage, who was left unguarded by the Rams' defense.

“No, I didn’t see the corner close down on that. That’s something that I should have been able to adjust out of," he said.