The 49ers activated defensive lineman Mykel Williams from the reserve/physically unable to perform list, the team announced Saturday.
Williams injured his knee in a Nov. 2 game against the Giants, ending his rookie season after nine games. He totaled 20 tackles and a sack.
Williams required surgery to repair an ACL tear and meniscus damage in his right knee.
The 49ers re-signed Ogbo Okoronkwo to the practice squad a day after cutting him from the active roster. The move was made to get Williams on the 53-player roster.
The 49ers elevated Okoronkwo and tight end Jack Stoll from the practice squad for Sunday’s game against the Seahawks.
Okoronkwo has appeared in four games with one start and has registered two tackles and a sack.