Fox said Monday he was relieved when he learned from the medical staff that Williams didn't break any bones in his foot.
"Anytime a guy gets hurt you just hold your breath," Fox said. "Not that this isn't painful and might require some time, but at least it's not broken and an extensive amount of time."
Williams, the Panthers first-round draft pick out of Memphis, injured his ankle on his first carry of the game when he was swarmed by a pile of defenders and is ankle got trapped under the weight of Cleveland Browns mammoth defensive tackle Ted Washington, who is listed at 365 pounds. He left the game and did not return.
"I couldn't tell if he rolled it or if he got rolled up on," Fox said. "It was pretty much a pile of bodies there so it was hard to tell."
Williams has yet to start for the Panthers, but he's given the offense a good burst of speed coming off the bench to spell starter DeShaun Foster against Minnesota and Tampa Bay.
The Panthers will need as many weapons as possible this week against a tough Baltimore Ravens defense.
With Williams out, Foster carried a season-high 24 times and netted his second straight 100-yard game.
"It's a tribute to everyone involved, our coaches for showing the patience and to DeShaun for running tough," Fox said.
Williams' status uncertain
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