However, Pellegrini believes Hart's time out of the first team will do him good.
"I think at this moment that maybe Joe needs a rest but we still have a lot of trust in Joe and he's still a very important player in our squad," Pellegrini told Sky News Arabia.
"It's very important for me as a manager - you don't have 11 players - you have 22.
"I analyse what they do every week - I talk with them.
"I am absolutely convinced he will come back to his performances of the last two years."