Both are listed as questionable, and Coach Dave Wannstedt said Friday there was no change in their condition. Thomas has a groin injury and Surtain an injured ankle. Thomas leads the team with 104 tackles, and Surtain is second in the league with six interceptions.
Tommy Hendricks will replace Thomas if he can't play. Hendricks has started one game this season, making four tackles against Jacksonville. Terrell Buckley and Jamar Fletcher are the Dolphins' backup cornerbacks.
Davis, who is second in the NFL with 992 yards rushing, sat out practice because of a nagging ankle injury for the third consecutive day.
He has not practiced since Carolina's 14-10 loss Sunday to the Houston Texans.
Second-year tailback DeShaun Foster will get his first NFL start if Davis doesn't play, Coach John Fox said.
"I think there has been improvement as the week has wore on," 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."
Defensive tackle Keith Hamilton of the New York Giants was indicted in Morristown, N.J., on a cocaine possession charge stemming from a traffic stop in May.
The case most likely will not be resolved for several months, meaning the 12-year veteran will not face disciplinary action by the NFL this season.
Under its substance abuse policy, the NFL does not fine or suspend a player until he pleads or is found guilty.
Wide receiver David Patten was put on injured reserve by the New England Patriots because of a knee injury and will sit out the rest of the season. A starter with the Patriots since 2001, he was inactive the last two games after catching only nine passes in six games.