"He will probably be deemed out this week because of the week itself being a quick turnaround and the nature of the injury," said Steelers coach Mike Tomlin, on the Steelers' Web site.
Polamalu has already missed two of Pittsburgh's four games this season due to his calf problems. He aggravated the injury in the first quarter against the Eagles, and spent the rest of the half sitting on the bench with his calf iced and didn't return for the second half.
Ryan Mundy and Will Allen are expected to fill in for Polamalu.
The Steelers have other health issues on defense. Linebacker LaMarr Woodley is considered doubtful for Thursday, while nursing a strained right hamstring. The injury is not considered serious, but Tomlin may avoid playing the former Pro Bowl star at this point in the season.
"Although there's more optimism regarding where he is ... we're at the early portion of the season and we've got to be smart with how we deal with that," Tomlin said.