49ers head coach Kyle Shanahan announced Monday that rookie linebacker Reuben Foster suffered a high-ankle sprain in the team’s Week 1 loss to Carolina, per Eric Branch of the San Francisco Chronicle (Twitter link). Matt Maiocco of NBC Sports Bay Area adds that Foster could miss four to six weeks. 
Foster went down in the second quarter Sunday, and the first-round pick initially thought he had broken his ankle.
“It was pain(ful),” Foster said (via ESPN.com’s Nick Wagoner). “I was a little scared, but at the same time, trust me, if you can’t put no pressure on it, then you should be worried, but when you put enough pressure on it, then you have got some hope. That’s all I was just hoping for. It was painful, but at the same time, I knew nothing was seriously damaged.”
Foster was viewed as a potential top ten pick before injury concerns weakened his stock. The Niners were not as worried about his surgically-repaired shoulder as other clubs and landed him at No. 31 overall.
Foster’s latest setback is unfortunate, but the team now knows that it will not be a season-ender.
Ian Rapoport of NFL.com first reported the injury. Photo courtesy of USA Today Sports Images.
He was looking good out there before the injury. Hope he has speedy recovery
I thought it was a failed drug test and off field incident that caused him to free fall in the draft
It was a shoulder issue too
I don’t remember him failing a drug test, just getting all pissy with the medical personal when he thought they weren’t fast enough. Pulling the ol ‘don’t you know who I am’ card