Davis, who leads the NFC with 992 yards rushing, missed his third straight day of practice Friday with a nagging ankle injury. He has not practiced since Carolina's 14-10 loss to the Houston Texans last Sunday.
"I think there has been improvement as the week has wore on," coach John Fox said. "(But) we're not going to do anything wrong as far as what is in the best interest of Stephen. If he's ready, he's ready. If he's not himself, we'll hold him out."
Second-year back DeShaun Foster will get his first NFL start if Davis doesn't play, Fox said.
Davis ran for 153 yards last week, but his ankle began to swell the day after the game.
He said Thursday during an NFL conference call with reporters that there was "no doubt" he would play Sunday.
He declined to comment Friday after watching practice.
Fox said if Davis is healthy he will get his regular number of carries. Davis has averaged more than 24 carries and 124 yards rushing a game this season.
The Panthers did get some good news Friday. NFL sack leader Mike Rucker returned to practice and participated in some drills. The team will decide Sunday whether to play Rucker, who has also been bothered by an ankle injury, Fox said.
The Panthers will not activate wide receiver Kevin Dyson this week. Signed during the offseason to become the Panthers' top receiving threat, Dyson tore his Achilles' tendon in spring drills and was expected to be out for the year.
His recovery has been faster than expected and he practiced with the team for the first time Wednesday.
This story is from ESPN.com's automated news wire. Wire index
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