49ers' Shanahan would be 'shocked' if Foster returned for Week 4

San Francisco 49ers head coach Kyle Shanahan said it's unlikely that rookie linebacker Reuben Foster will be available for Week 4's contest against the Arizona Cardinals.

Foster suffered a high ankle sprain in the 49ers' Week 1 loss to the Carolina Panthers.

"I'd be shocked if he came back this week," Shanahan told reporters Friday.

Foster recorded three tackles in his professional debut. The 23-year-old was selected with the 31st overall pick in the 2017 NFL Draft out of Alabama and is expected to be a major component of the 49ers' young, rebuilding defense.