"Carolina Panthers rookie running back Jonathan Stewart may not play Sunday against the Oakland Raiders after missing his second straight day of practice on Thursday with a heel injury.

Stewart was wearing a walking boot on his left foot Thursday.

"The medical people said he wouldn't be able to go today," coach John Fox said after practice. "It's day to day and we'll evaluate it tomorrow, but anytime you don't have a guy out there it's always concerning."

Stewart said the heel began bothering him during Carolina's 27-23 win over Arizona on Oct. 26, a game in which he was held to just 10 yards on eight carries.

He described the heel as "sore."

"It's a sharp pain in my heel," Stewart said. "I have to run the ball and it hurts every time I press off on it. I'm just trying to get it as well as I can right now."

Fox wouldn't rule out Stewart playing Sunday against the Raiders, but he typically doesn't play players who've missed the entire week of practice. So if Stewart doesn't get back on the practice field Friday, he likely won't play.

If Stewart can't go, Nick Goings would be Carolina's backup running back behind starter DeAngelo Williams. Also, fullback Brad Hoover might see additional carries.

It's unclear if this could develop into a long-term injury, but right now the Panthers are hoping rest will do the trick.

"We have to wait and see. It's not definite he won't play this week," Fox said."