Ulbrich placed on IR

The 49ers signed former Chargers inside linebacker Matt Wilhelm to take his spot on the roster. Wilhelm will serve as a backup at inside linebacker. He also can play on special teams. Wilhelm (6-4, 245) has played in 71 career games with 21 starts after being a fourth-round pick of the Chargers in 2003. He played under current 49ers defensive coordinator Greg Manusky. * * * Coach Mike Singletary said safety Michael Lewis is expected to return to action this season. Lewis has sustained three concussions since mid-August, but Lewis' concussions symptoms have not been nearly as severe as Ulbrich's. * * * Offensive lineman Adam Snyder will continue to split time, but it won't be at right tackle. Snyder has been moved to right guard, where he and Chilo Rachal will share playing time for the near future, Singletary said. Veteran Tony Pashos will take over as the full-time right tackle, where he had been splitting time with Snyder the past four games. * * *