Harris made his first start against San Francisco on Sunday, but left in the first quarter with a broken bone in his right leg.
He played because regular starter Zach Strief was not ready to return from his left groin injury, and Strief's primary backup, Charles Brown, hurt his right knee a week earlier. Vitt declined to say whether Strief would return at Atlanta on Thursday night, saying only that the possibility "looks good."
Strief practiced on a limited basis on Tuesday, as he did last week. If he cannot play, William Robinson, who was signed last week and stepped in from Harris against the 49ers, would start.
"Our right tackle situation is going to fine in this game," Vitt said. "There are a lot of ways that we can help that position. There are a lot of ways that we do help that position. We have the next-man-up theory that we have always gone to. There is not going to be any built-in excuse for us not to try to play our best football."
The Saints filled the open roster spot with tight end Michael Higgins from their practice squad. He could fill in for David Thomas, who was limited with a knee injury.
Those missing Tuesday's practice included Brown, defensive tackle Tom Johnson with a sore back, defensive end Junior Galette with a left ankle injury, kick returner and receiver Courtney Roby with shoulder and ankle injuries and safety Isa Abdul-Quddus.
Cornerback Corey White returned to practice on a limited basis from his left knee injury.