"Carolina Panthers rookie running back Jonathan Stewart didn't practice Wednesday because of a heel injury. Coach John Fox wouldn't speculate on Stewart's availability for Sunday's game in Oakland.

But DeAngelo Williams, the team's starting running back, thinks Stewart will be OK.

"It was a precautionary thing," said Williams. "I don't think he's hurt."

Williams said having Stewart, who leads the team with five rushing touchdowns, is important.

"It makes a huge difference," said Williams. "He hasn't missed a game thus far. I'm not a trainer, but they do a great job getting us back on the field. I don't think he'll miss time."

Starting offensive linemen Jeff Otah and Ryan Kalil, who have been out with knee injuries, returned to full participation, as expected. Otah has missed four games with a high ankle sprain; Kalil has been out for three games with a sprained ankle.

"It felt good," Otah said Wednesday. "I was happy to be out there.

"I could block when I wanted to and didn't have to favor my ankle.

"Unless something happens, I expect to play (against the Raiders).""