The 49ers activated defensive lineman Demarcus Dobbs after he served a one-game suspension for violating the NFL substance abuse policy. The club announced it waived-injured defensive lineman Will Tukuafu to create room for Dobbs on the 53-man roster. Tukuafu was not listed on the 49ers' injury report last week and he did not play in the team's season opener on Sunday against the Green Bay Packers. Tukuafu a two-year NFL veteran saw playing time at defensive tackle and fullback in 14 regular-season games last season and all three playoff games. Dobbs also one of the 49ers’ top special teams players joins a defensive line group that consists of five other players: Justin Smith Ray McDonald Ian Williams Glenn Dorsey and Tony Jerod-Eddie.