49ers giving quartet a two-way look

San Francisco's Will Tukuafu has spent most of his football life chasing down running backs. The 49ers hope he can now help Frank Gore and the rest of their backfield handle other defensive tackles with the same agenda. The 293-pound Tukuafu is getting some additional work at fullback during the 49ers' organized team activities this offseason. He even managed to catch a touchdown in practice Tuesday, taking a short swing pass from quarterback Alex Smith then rumbling into the end zone. It might only be June but coach Jim Harbaugh is already looking for ways to keep opponents guessing - and maybe save some space on the roster at the same time. Tukuafu is one of four players San Francisco is using on offense and defense during its offseason workouts.