Welker appeared to suffer the injury on his last catch of Sunday's loss in Pittsburgh. He was grabbed by Steelers safety Troy Polamalu around the shoulders and in the neck area and taken down with about six minutes remaining in the fourth quarter. Welker was slow to get up, but remained in the game.
After the game, Welker spoke to reporters, and on Wednesday he held a conference call with New York media, but did not appear in the Patriots locker room.
Remaining out of action on Thursday was linebacker Dane Fletcher, the lone player not practicing. Fletcher has missed the past several weeks of practice, and is listed with a thumb injury.
Players were in full pads, after practicing on Wednesday in light shoulder pads.
Mike Rodak is a regular contributor to ESPNBoston.com. Information from ESPNBoston.com's Mike Reiss and Chris Forsberg was used in this report.