SANTA CLARA, Calif. -- Will Tukuafu departed the San Francisco 49ers three months ago as more of a defensive tackle than a fullback.Now it appears he returns as a fullback. The 49ers announced they signed Tukuafu and he is listed as a fullback. He takes the place of starting fullback Bruce Miller on the roster. Miller was placed on injured reserve.It is doubtful Tukuafu will take Miller's spot in the lineup. That will likely go to reserve running back Anthony Dixon.