SAN FRANCISCO — Unless Mike Singletary is headed to church, you won't catch the San Francisco 49ers' new coach in a suit and tie on Sundays.

Nearly 16 years after he retired, Singletary is finally comfortable not wearing pads and a helmet on game days. He's just not planning to carry on the sharp-dressed tradition of Mike Nolan, his coaching mentor and boss until last Monday.

Although the Hall of Fame linebacker is quietly thrilled about his interim head coaching debut against the Seattle Seahawks, he's hoping to keep the focus off himself and on the players whose struggles led to Nolan's midseason firing.

"The cameras may be on me, but the game is on them," Singletary said.

Singletary only got into coaching in 2003, a decade after he retired from a memorable career in Chicago. Several former Bears, including Dan Hampton, Richard Dent and Steve McMichael, called this week with support and good-natured razzing, and Singletary planned to seek the counsel of coach Mike Ditka before he steps into Candlestick Park.

He also planned to call Nolan, who restored the 49ers (2-5) to a measure of respectability, but couldn't win consistently.

"Those are my friends," Singletary said. "Those are my mentors, and without them, there would be no me. I had to learn that the hard way."

The 49ers' four-game losing streak prompted Nolan's departure, and Singletary has just nine games to put himself in contention for the permanent job. He understands the fundamentals of being a head coach, from the red challenge flag to clock management, but knows he can only hone them through practice.

"I'm sure I'm going to make boneheaded decisions," Singletary said. "Get that out of the way. There are guys that have been coaching for 20, 30 years, and they make boneheaded decisions, so how do I think I'm going to be any different?"

Another prime candidate for the job — at least in the minds of 49ers fans — will be on the opposite sideline.

But this meeting of struggling NFC West rivals is no job interview for Mike Holmgren, who has too many problems with his own moribund Seahawks (1-5) to worry much about the possibility of returning to San Francisco next season or in 2010.

Instead, Holmgren is just as curious as any other native San Franciscan to see how Singletary will do in tough circumstances.

"It's interesting when you have the great, great, great players like Mike was who choose to go into coaching," said Holmgren, who doesn't know Singletary well. "Coaching isn't as glamorous as just being the star football player. But clearly he wants to do this, and now he gets his crack at it."

Holmgren has promised his wife he'll take the next year off to ride his motorcycle, hit the beach, play with the grandkids and tend to their new house near Santa Cruz — a beautiful 45-minute drive from the Niners' training complex, fans will undoubtedly remember.

Such speculation will last long after Sunday, when the teams hold the rematch of their meeting six weeks earlier in Seattle, won 33-30 in overtime by the 49ers. The clubs are a combined 2-7 since then, bringing up the rear in an unimpressive division.

The 49ers will put their faith again in J.T. O'Sullivan, whose learning curve was too gradual to save Nolan's job. With 10 interceptions and nine fumbles, O'Sullivan is taking much of the heat for the 49ers' woes.

But O'Sullivan impressed the Seahawks with his play in the 49ers' win in Seattle, passing for 321 yards while leading the tying and winning drives.

"He really did do a great job against us last time creating plays, getting first downs with his legs and buying time for him to make some great throws," Seahawks defensive end Patrick Kerney said. "I probably didn't appreciate his elusiveness going into the first game. I probably underestimated that."

And at least O'Sullivan is healthy, even after 29 sacks. Seattle quarterback Matt Hasselbeck isn't expected to play after missing the two most important days of practice during the week, likely leaving the struggling offense in the hands of Seneca Wallace, who hasn't done much to make fans confident.

Wallace started in San Francisco two years ago while Hasselbeck was out with a knee injury, setting career highs in completions (19), attempts (31) and yards (252) while also throwing three interceptions in a 20-14 loss. During the Seahawks' 23-3 win in San Francisco last year when Hasselbeck was healthy, Wallace still got on the field again for a handful of plays, throwing a pass, catching an 18-yard throw and even running the ball.

"A lot of guys are stretching to try to make plays, because we're obviously not winning games," Wallace said. "Guys are trying to make up for other guys, trying to make plays. Sometimes it hurts you in the long run. We've just got to continue to keep working through it and hope for the best."