Enough that Harbaugh is sticking with Kaepernick under center — for now, anyway — as his team gears up for Sunday’s home game against the Miami Dolphins at Candlestick Park.

“Just a winning quarterback performance in tough circumstances,” Harbaugh said Monday. “In the evaluation, I thought Colin played well, did a lot of really good things, made some good decisions. … I thought some real positives to take away from his performance.”

Yet Alex Smith isn’t out of this mix yet, either. Another sub-par performance by Kaepernick could have Harbaugh going back to the 2005 No. 1 overall draft pick for the final December push toward the playoffs. The reigning NFL coach of the year is leaving every option open down the stretch.

A day after a 16-13 overtime loss at St. Louis, Harbaugh accepted the blame for the fourth-quarter pitch that was fumbled by Kaepernick and led to Janoris Jenkins’ 2-yard fumble return for a touchdown and ensuing 2-point conversion that tied the game. Harbaugh didn’t call the play, but relayed it through the headset to Kaepernick.

“Responsibility-taking starts with me on that option play that resulted in the nightmare scenario,” Harbaugh said. “Position of the game that where I should not let that play be called. So I take responsibility for that.”

At 8-3-1, the Niners are prepared for a challenge from the Seahawks (7-5) in the NFC West after Seattle won in overtime at Chicago on Sunday. The teams play at Seattle in the second-to-last game on Dec. 23.

Everybody around San Francisco is looking for a strong finish by a team that has set its sights on the Super Bowl since moments after last year’s near miss: a 20-17 overtime loss to the eventual champion New York Giants in the NFC title game.

“You’re mad to the point where you don’t really feel anything right now,” linebacker Patrick Willis said Sunday in St. Louis.

After this week’s home game with Miami (5-7), San Francisco also must travel to New England in another daunting road task. The 49ers are certainly frustrated with the way their two games against the Rams wound up after a 24-24 tie on Nov. 11.

“We expect to execute,” left tackle Joe Staley said. “We didn’t execute. Late in the season we shouldn’t be having games like this.”

David Akers missed another key field goal in what has been a difficult stretch for the kicker. His 51-yard attempt with 4:16 remaining in overtime went wide right, only three weeks after he missed left on a 41-yard try also in overtime against the Rams.

While Akers was listed on last week’s injury report with a pelvis issue, he looked fine during practice from as far out as 50 yards. Harbaugh expects him to play against the Dolphins — even after the team brought in a couple of backup options for tryouts last Tuesday.

Akers, who set an NFL single-season record with 44 field goals in 2011, has made only 15 of his last 24 attempts.

“We’ll see what his health status is this week, but all indications are he’s working through something,” Harbaugh said. “He’s kicked well in practice. He’s kicked well in games. I thought the one that he hit in the ball game that was missed was well hit. It just didn’t go in.”

Harbaugh will call on all of his players to improve during practice this week and challenge each other, saying “we don’t lay it on anybody’s particular doorstep.”

“It’s a tough loss,” he said. “It’s one you wake up this morning, and that gut-wrenching feeling is still there. The positive things are we still have a quarter of the season to play. Four games, we’re in position to control our own destiny and bounce back. Certainly a bit of an edge, I would expect, because we all take responsibility we didn’t get it done this week.”

Notes: Harbaugh said he met with defensive end and special teams regular Demarcus Dobbs regarding his arrest Friday morning — on his 25th birthday — for suspicion of driving under the influence and marijuana possession. Harbaugh said Dobbs is expected to be available for Sunday’s game after he didn’t travel for the Rams game. “That’s a situation we’re handling internally,” Harbaugh said. … Harbaugh said he had no update on the shoulder injury sustained by WR Mario Manningham.