USC defensive tackle Antwaun Woods, who underwent surgery for an injured pectoral muscle, will be sidelined for the Dec. 27
Woods, a junior, attended Wednesday's practice but players were not made available to the media.
Woods was injured during practice last week.
Nebraska features running back Ameer Abdullah, who has rushed for 1,523 yards and 18 touchdowns, and quarterback Tommy Armstrong Jr., who has rushed for five touchdowns.
"We have to be prepared for both guys running the football right at us," Sarkisian said.