Pouncey left in the middle of Pittsburgh's Week 12 win over Kansas City with an illness. It was reported that he was dehydrated and had lost some weight. Polamalu's concussion-like symptoms were said to be improving, and he was likely held out for precautionary reasons.
OLB Chris Carter also did not practice.
It's still early in the week, and neither Polamalu nor Pouncey are currently. expected to miss Sunday's game. If they did, however, like they did for most of Week 12, LG Doug Legursky would move to center, and Chris Kemoeatu would replace Legursky. Ryan Mundy would fill in for Polamalu.
Injuries are a part of the NFL, especially late in the season. With the return of LaMarr Woodley to the lineup expected this week, it would be frustrating for the Steelers to have more starters miss time with injuries. This team hasn't had a full compliment of starters since Week 1.