Ellis was injured late in the second quarter and had to be helped off the field. He was later carted off the sidelines.
"I've been putting pressure on it and trying to walk on it a little bit," he said after the Saints' 46-34 win. "We'll have to see Monday."
The Saints were already without starting nose tackle Kendrick Clancy, who hasn't played since the first game of the season because of a right knee injury.
Fullback Heath Evans also injured his right leg late in the game.
Copyright 2009 by The Associated Press