Hart was replaced by City reserve goalkeeper Costel Pantilimon for the 2-0 midweek Capital One Cup victory over Newcastle after a costly error against Chelsea last weekend.
And the Chilean suggested the England number one would be treated like any other player after he refused to confirm he will start in goal for this weekend's game at the Etihad.
"Tomorrow you will know the answer," Pellegrini said. "It is a decision I have to take every week with 22 players of the team."
Pantilimon produced an eye-catching display in Wednesday's game against Newcastle to put him firmly in contention for his first Premier League start this weekend.
Pellegrini refused to be drawn on how disappointed Hart was not to feature in the game as City look to preserve their 100% record at home - a run which has seen them notch 13 goals in their opening four league matches.
"You must ask Joe - I can't answer for him how disappointed he was," Pellegrini told reporters.
"All of you, and the players, and me all saw what happened. But he is a football player and every week he is under the same pressure.
"I am always careful with all the players, not only Joe."
What is certain about City's team for the Norwich contest is that it will not feature Stevan Jovetic (calf), Javi Garcia (unspecified) - who both picked up injuries in the Newcastle game - or Vincent Kompany.
City skipper Kompany has missed the last four matches due to a thigh problem, and regarding the Belgium defender, Pellegrini said: "Vincent is progressing but I think it will be after the international break maybe that he will be fit - before that I think is difficult.
"He is a very important player but I think we have a strong squad just for this case. Other players can play.
"We played the last five matches (Kompany's last appearance was when he came off in the first half of the victory over Everton on October 5), won four and lost just one against Chelsea, and I think we deserved more.
"So he is always an important player, but I think we can play also without him."