Mike Singletary was on the sideline in place of head coach Mike Nolan, who was attending a memorial service for former 49ers coach Bill Walsh.

It gave Singletary a taste of being a head coach, a job he has aspired to since entering coaching in 2003.

"It was a little bit biased, you know, defensive-oriented here," said Singletary, now in his third season as San Francisco's assistant head coach/defense.

Not many expect Singletary will be around for a fourth season with San Francisco in 2008. A Hall of Fame linebacker with the Chicago Bears during his playing days, Singletary now is a hot coaching commodity who appears destined to be guiding his own NFL team in the near future.

Singletary, 48, had interviews with three teams this offseason for their vacant head-coaching positions, and he nearly got the Atlanta job that went to Bobby Petrino because of his offensive background.

A forceful presence on and off the field, Singletary says he has been grooming himself to be a head coach since he entered coaching as a Baltimore Ravens assistant in 2003. He spent two seasons with Baltimore before following Nolan — the Ravens' defensive coordinator from 2002-2004 — to San Francisco in 2005.

"When the time comes, I will be ready," Singletary said. "I knew when I came into the league I wanted to be a head coach, but it's not something I focus on. The most important thing for me right now, day in and day out, is to make sure that I am the best (assistant head coach/defense) that I can be. I'm working towards being the best that I can be today."

Singletary played in 10 Pro Bowls and was named All-Pro eight times during his stellar career with the Bears from 1981-1992. He then spent time as a motivational speaker and authored three books before returning to the football arena, where he won the Walter Camp's "Man of the Year Award" in 2001 based on his leadership and contributions within the profession.

Nolan doesn't expect it to be long before Singletary takes the next step in his coaching climb.