The San Francisco 49ers are set to activate linebacker Dre Greenlaw from the physically unable to perform list, marking a potential return after his Achilles injury during the Super Bowl against the Kansas City Chiefs.

Coach Kyle Shanahan announced the opening of a 21-day practice window for Greenlaw, who has been sorely missed amid a season plagued by injuries to key players. With a challenging schedule ahead, the 49ers are in desperate need of reinforcements as they chase a playoff spot.