The San Francisco 49ers signed numerous offensive players on Thursday and Friday, but they did sign one defensive player of note in linebacker Malcolm Smith. They also signed linebacker Brock Coyle and defensive back Don Jones, but they are primarily special teams players.
Smith joins the 49ers after two years with the Oakland Raiders, and four years with the Seattle Seahawks. He did not become a full-time starter until he joined Oakland, but his time in Seattle got him accustomed to the 4-3 defense in which he will likely play outside linebacker.