The San Francisco 49ers on Monday added nose tackle Glenn Dorsey to the 53-man roster from the short-term injured reserve list, three weeks after he began practicing following his biceps injury suffered in training camp.
In the corresponding roster move, the Niners placed nose tackle Ian Williams on season-ending IR with his left fibula injury suffered Nov. 9 at New Orleans.
A year ago, Williams was lost for the year in the season's second game with a broken ankle and Dorsey started the season's final 13 regular-season games and three playoff games. Dorsey, the Kansas City Chiefs' No. 5 overall pick in the 2008 draft, had 41 tackles last season with two sacks.
Williams, meanwhile, started eight of the nine games in which he appeared this season with career highs in tackles (41), sacks (one) and passes defensed (one).
Coach Jim Harbaugh also said the 49ers would open linebacker NaVorro Bowman's 21-day window Tuesday for practicing with the team. Bowman is still recuperating from a devastating left knee injury suffered in last January's NFC title game at Seattle.