San Francisco 49ers defensive tackle Justin Smith will undergo surgery this week to repair a partially torn triceps, Comcast SportsNet Bay Area reported Monday. Smith will require about three months of rehabilitation following the surgery. Smith missed the team's final two regular-season games after suffering a 50-percent tear of his left triceps on Dec. 16 against the New England Patriots. He returned to play in the 49ers' three postseason games and wore a brace on his left arm. He played in 14 games this season and had 3.0 sacks, his second-lowest total in his 12-year career. He did not have any sacks in the playoffs. Smith is expected to make a full recovery in time for the opening of training camp in late-July.