His new title is ?interim head coach,? but he might as well be known as ?Mike the Plumber.?

That?s because Mike Singletary has a lot of leaks to fix for the 49ers in the second half of the season.

It?s been an eventful first eight games for the 49ers. Team executive Jed York bid a tearful farewell to coach Mike Nolan on Monday, Oct. 20. Nolan?s firing came just a couple hours after he delivered his final press conference to the media to talk about the loss to the New York Giants.

Singletary has a lot of tasks in the final two months of the season. He must find a way to tighten up the 49ers? leaky defense. And the team?s offense has gone in the tank in large part due to quarterback J.T. O?Sullivan?s inability to hold onto the ball.

And now Singletary has apparently set his sights on finding the person responsible for spilling the details of his pants-dropping halftime speech to his team. Singletary said he wanted to dramatize how the 49ers were getting their behinds whipped last week against the Seattle Seahawks.

?It?s unfortunate, and we will find out who?s leaking this information out of the locker room because what happens in the locker room should be sacred and stay there,? Singletary said Friday on a Chicago radio interview.

Here?s a rundown of some of the highlights and lowlights of the 49ers? season to date:

Offensive MVP: Running back Frank Gore has accounted for 37.3 percent of the team?s offense. He ranks second in the NFL with 940 yards from scrimmage. Gore is 371 yards shy of becoming the first player in team history to rush for 1,000 yards in three consecutive seasons.

Defensive MVP: Linebacker Patrick Willis leads the team in tackles and passes defensed. He also provided one of the highlights of the season with his 86-yard interception return for a touchdown to spark a Week 2 victory over the Seahawks.

Making history: The 49ers became the first team in NFL history to return blocked field goals for touchdowns in back-to-back games. Since 1970, the 49ers had scored on only three blocked field goals prior to this season. Donald Strickland and Nate Clements got touchdowns against the Eagles and Giants on kicks blocked by Ray McDonald and Manny Lawson, respectively.

Disappointments (offense): Coordinator Mike Martz insisted he was ?not displeased? with O?Sullivan just three days before the quarterback was benched. O?Sullivan has thrown 11 interceptions and lost six fumbles ? not including another fumble that resulted in a safety. Honorable mention: Tight end Vernon Davis, the No. 6 overall pick in 2006, has just 16 catches for 196 yards.

Disappointments (defense): Lawson was a first-round pick in 2006, but the 49ers turned him into a bit player for most of the first half of the season. Finally, it appears as if they want to get him on the field, and he responded with a solid showing in the most recent game. Honorable mention: Safety Mark Roman has made little impact. In 40 career starts with the 49ers, he has just one interception.

Biggest collapse: The 49ers led the Philadelphia Eagles by nine points at the start of the fourth quarter. But they could not hold the lead, getting outscored 23-0 in the final quarter. That game ? more than anything else ? led to Nolan?s firing as head coach eight days later.

Best play: On a third-and-7 deep in 49ers territory, Gore made an incredible flying block to pick up a blitz, allowing O?Sullivan enough time to throw a deep pass to Isaac Bruce against the Seahawks in Week 2. The play gained 33 yards, and set up the game-winning field goal in overtime.

Worst play: Rather than attempt a 47-yard field goal that would?ve pulled the 49ers to within seven points late in the first half, Singletary decided to go for it on fourth-and-4 last week against the Seahawks. Josh Wilson intercepted O?Sullivan?s pass and returned it for a 75-yard touchdown with :31 left in the half. O?Sullivan was benched, and Singletary had another surprise waiting for his team during his halftime talk.

For more on the 49ers, go to Instant 49ers at http://blog.pressdemocrat.com/49ers. You can reach Staff Writer Matt Maiocco at 521-5492 or matt.maiocco@pressdemocrat.com