Manning, speaking to The Indianapolis Star, said he will sit next to quarterbacks coach Ron Turner at Lucas Oil Field and be involved in the locker-room routine before the game and at halftime.
It will serve as a welcome change for Manning, more than two weeks after neck surgery that has sidelined him for at least two months and kept him away from the Colts' first two games.
"I walked around for a while angry, in a bad mood. ... 'Woe is me,' " Manning told the newspaper Friday. "I've gotten over that. It doesn't do any good."
Manning wouldn't speculate on when and if he could return to the field after undergoing his third surgery in 19 months. The Colts have kept him on the active roster despite the latest procedure on Sept. 9.
"I do hope to get healthy, and when I'm healthy and cleared to play, I want to be out there," Manning said. "But I'm off the clock as far as that goes. I'm just trying to follow the doctors' orders and get healthy."
Manning was back at Colts practice Wednesday, the second time this week he was seen taking laps around the practice field.
"My first priority was doing what I needed to do for my long-term health," said Manning, who said he hasn't thought about the possibility of retirement. "At the same time, it should help me in the short-term.
"I have a good attitude. I hope things continue and get better."
Manning had started 227 consecutive games, including the playoffs.
"This is new to me," he said. "I try to have a good perspective, I really do."
In addition to providing input to the Colts' coaching staff Sunday, Manning has also helped them prepare for the Steelers this week, working with offensive coordinator Clyde Christensen and quarterback Kerry Collins.
"He's such a great resource," Christensen said. "Nobody knows this offense better than him. He's a genius on protections. He's a genius on game plans."
But Manning isn't warming to his temporary role.
"Eventually I'd like to get back on the sidelines just to be around," Manning said. "You really miss that.
"Trust me, I'm bleeding with everyone else. It's still 'we.' It's not 'them.' I'm right there in it with them."
Information from The Associated Press was used in this report.