Greenlaw (groin) is expected to be activated from IR before Sunday, according to head coach Kyle Shanahan, Matt Barrows of The Athletic reports.
Greenlaw was designated to return from IR on Nov. 17. He suffered the injury in the 49ers' first game of the season and required core muscle surgery to repair it. The return of the third-year linebacker would be a boost to the 49er defense, as they host the Vikings on Sunday.