49ers keep NT Ian Williams with 5-year deal

In December, before the regular-season finale, he noted the team probably wanted to make sure he could remain upright for 16 games. After two injury marred seasons, Williams did just that and the 49ers have locked up to their most prized in-house free agent with a five-year deal, a league source said. Williams, 26, was a stabilizing force in the middle and collected 65 tackles, one sack and one forced fumble in 2015. Despite his lack of experience, Williams, who had played 15 games in his first four seasons, was named one of the team’s four defensive captains before the season. Williams will return to a defensive line that will include tackles Quinton Dial, who recently signed a three-year, $16.5 million extension, and Arik Armstead, last year’s first-round pick.