FOXBORO, Mass. — Quarterback Tom Brady took part in the Patriots' walkthrough Wednesday, but center Dan Koppen was missing at the start of practice for unspecified reasons.

However, according to the Patriots' public relations staff, Koppen did participate in practice after the 15-minute media session. Koppen did not appear on the injury report, so he should be considered healthy.

If, for some reason, Koppen couldn't play Sunday in Chicago, the Patriots could use Dan Connolly, Ryan Wendell and Rich Ohrnberger at center. Connolly, who is the starter at right guard due to Stephen Neal's season-ending shoulder injury, might be the most likely candidate to play center, which would then put Wendell at right guard. However, Connolly and Wendell could be interchangeable at those two positions.

Cornerback Jonathan Wilhite (hip) and defensive lineman Mike Wright (concussion) were also absent from the walkthrough, which was held in the Dana-Farber Field House. With the Patriots trying to catch up on time during this short week, Wednesday's focus could have been on teaching and installation, which would make the walkthrough more beneficial.

This is also the first time Brady has taken part in the Patriots' initial practice of the week since the first week of November.