With two players at the same position scheduled to reach the free-agent market on Tuesday, the 49ers reached a contract extension with nose tackle Ian Williams. Williams, who signed with the 49ers as an undrafted rookie from Notre Dame in 2011, has appeared in just four games in two seasons. But he has a chance to take on a greater role because two players ahead of him are unsigned. Pro Football Talk first reported the deal, which has been confirmed. PFT reports the deal is two years, $3.2 million. He was originally signed through the 2013 season. Isaac Sopoaga and Ricky Jean Francois are both scheduled to be free agents, and are expected to draw some interest on the open market.