NEW YORK -- As the uncertainty surrounding Rasheed Wallace's left foot injury lingers, members of the New York Knicks organization fear Wallace will be out for an extended period, possibly for the entire season, two league sources told ESPNNewYork.com.

Wallace has been out since Dec. 15 with a stress reaction in his left foot.

Knicks coach Mike Woodson said last week that he hoped Wallace would begin running this week, but he told reporters in London on Wednesday that Wallace, 38, has yet to do so.