The kicker certainly hasn’t been himself lately.

After missing a winning field goal in overtime in two of the last four games, Akers and his fellow 49ers (8-3-1) special teamers are as perplexed as anybody about what has gone wrong. The six-time Pro Bowl kicker is 21 for 30 on field goals this season.

“David really brings a passion and emotion to our unit,” Jennings said. “That’s one of the contributing factors as to why he’s been so great throughout his career, and then also why if things don’t go the way we’d like them to, it can be particularly hard on him.”

Just a year ago, Akers set an NFL single-season record with 44 field goals. He missed only eight kicks — and none of them of such magnitude.

The success of last season has made this year’s shortcomings maddening.

Akers missed a 51-yard attempt with 4:11 remaining in overtime of San Francisco’s 16-13 loss at St. Louis on Sunday. The kick sailed wide right by mere inches and came only two weeks after he missed left on a 41-yard try — also in overtime against the Rams before the game ended in a 24-24 tie.

Akers has made only 15 of his last 24 attempts, but he has tried to focus on his technique, not his misses. And while he watches film of most kicks, he hasn’t been able to pinpoint what has gone wrong — or at least he’s not saying as much publicly.

“I have no idea,” Akers said. “I’ve done it for a lot of years. Lot I’ve gone through. Some I’ve missed. I don’t really contemplate on those issues. If I’ve noticed something, I probably would have made a correction.”

Akers was listed on last week’s injury report with a pelvis issue, though he looked fine during practice from as far as 50 yards. Niners coach Jim Harbaugh expects Akers to play at home against the Dolphins on Sunday, which just so happens to be the kicker’s 38th birthday.

Harbaugh had brought in Billy Cundiff and Nate Kaeding for tryouts last week but said he isn’t concerned aboutAkers’ psyche.

“David, as far as mindset, he’s a professional,” Harbaugh said. “He’s been in every situation imaginable. He takes responsibility and knows it’s his job to put it through the uprights. As far as his mindset, it’s as a pro.”

Akers’ struggles have come about in swift and stunning fashion.

Aside from his 44 made field goals last season, Akers also set a record for most attempted (52) and most points without a touchdown (166). That eclipsed the 49ers’ previous best for overall points — set by Hall of Fame receiver Jerry Rice, who scored 138 points in 1987.

In San Francisco’s season-opening win at Green Bay, Akers even tied an NFL record with a 63-yard field goal that bounced off the crossbar and through the uprights. Akers’ mouth dropped open and his eyes popped wide as he threw his arms into the air in celebration and disbelief.

His teammates mobbed him after the record-tying kick, and Akers has excelled so much he has become one of the team’s leaders. Some teammates are still surprised Philadelphia let him go in 2011 after 12 seasons. He holds Eagles franchise record for points, field goals, extra points, games played in the regular season and in the playoffs.

The success Akers has enjoyed for most of his career has made his recent decline even more difficult to watch for teammates, especially Jennings and Lee — part of a tight trio with Akers in the locker room.

“Last year, I would say, was one of my greatest years as a player,” said Jennings, who’s in his 13th season with the 49ers. “Now I would say with some of our performances this year, this has been one of the more frustrating years of my career. I think we all share that. I think we all go through it.”

San Francisco is still counting on Akers to regain his rhythm.

The NFC West-leading 49ers are trying to hold off Seattle (7-5) to win a second straight division crown and perhaps even another first-round playoff bye should they finish in the top two in the conference. After all, there’s a good chance any success might not be reached without Akers’ powerful left leg, which is always magnified in such massive moments — especially when things don’t turn out well.

“There’s no uglier football than bad special teams. It’s the height of ugly football,” Jennings said. “We have the ability to be the best in the league, and the frustration comes from not being in that position. So until we’re re-established as the best special teams unit in the league, there’s going to be some struggles and some frustration.”

NOTES: RB Frank Gore wore a brace around his left wrist. He said he tweaked his wrist stiff-arming a defender and it’s not anything that will keep him out of Sunday’s game. … DL Demarcus Dobbs said he made “a dumb mistake, a dumb decision” when he was arrested early Friday morning on suspicion of driving under the influence and possession of marijuana after a single-car accident. Dobbs said he takes “full responsibility” for his actions and isn’t sure if he’ll be activated against Miami. … Harbaugh hinted on his weekly KNBR radio spot Tuesday that second-round pick LaMichael James will see playing time soon. James, the speedy running back out of Oregon who has not played this season, said Harbaugh hasn’t told him when he’ll play.