Tollner, the former USC and San Diego State coach, also is a longtime NFL assistant who served on the 49ers' coaching staff from 2002-04, with two years as quarterbacks coach and one season as offensive coordinator. He was the Detroit Lions' offensive coordinator for part of the 2005 season.

"Ted has great experience with over 30 years in the NFL and in college coaching, and is well respected in the football community," 49ers coach Mike Nolan said. "He will be a tremendous asset to the 49ers organization. We will continue to make every effort to improve our team."

San Francisco's offense hasn't recovered since coordinator Norv Turner abruptly left the job in February to take over the San Diego Chargers. The 49ers hope the 67-year-old Tollner can help an offense that's at the bottom of the NFL in most statistical categories under first-year coordinator Jim Hostler.

The 49ers (2-8), who have an eight-game losing streak while going 11 straight quarters without a touchdown, are last in the league with 113 points and 218.6 yards per game — nearly 50 fewer than the next-worst team. They're also last in total plays from scrimmage (503), yards per play (3.9), third-down conversion percentage (28 percent) and time of possession (25:58).

Nolan gave a vote of confidence to Hostler on Monday, insisting he wouldn't fire the former quarterbacks coach who took over for Turner.

"Jim is an easy scapegoat for people to jump on," Nolan said. "The production is not as good as it was last year. I wouldn't put all that on Jim. He's an intelligent guy busting his tail. It's an offensive staff's responsibility to get it done."

The 49ers also signed quarterback Drew Olson to the practice squad, waiving guard Sean Estrada to make room. Olson, the former UCLA star and a Bay Area native, spent last season with Baltimore before briefly catching on with Carolina this month.