"Yaya has a problem with his knee so he is not able to play," Pellegrini told a news conference at the Parc des Princes.
Toure has been struggling with his knee for the past month and missed Saturday's 4-0 Premier League win at Bournemouth.
Hart picked up a calf injury in last month's 1-0 defeat at home to Manchester United but is back to full fitness after training with the team on Tuesday.
"Hart has worked without any problem in the last day,” the chilean said. “He has had medical and physical tests and has no problems to play."
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City will be playing in their first Champions League quarter-final, while it is French champions' PSG's fourth consecutive appearance at that stage of the competition.
"They (PSG) are ahead of us but every team evolve in their own way," City defender Eliaquim Mangala told a news conference.
"I respect PSG, Zlatan (Ibrahimovic), (Edinson) Cavani, (Angel Di Maria), but I'm not scared.
“Both teams have a chance to continue to the next stage -- the chances are 50 percent for each team," Pellegrini said.
“It’s important for the club, the fans, the players. Last season we couldn’t continue as we faced a strong team like Barcelona," he added referring to City's last 16 defeat.
"Now we’ve improved this season -- we've topped our group for the first time and qualified from the last 16 for the first time."
(Reporting by Julien Pretot; Editing by Ken Ferris)
