Hart made his first Premier League appearance in almost two months in Saturday's win over Fulham after getting the nod ahead of Costel Pantilimon.
Despite conceding two goals on his return between the posts, Pellegrini will keep faith with Hart for the visit of Liverpool next week.
"At the moment Joe is going to play against Liverpool. He did well and he deserves to play the next match," said the City boss.
"In every match, we could play with 11 different starters, but at the moment Joe will continue to play.
"When I put Pantilimon in the starting XI I spoke with Joe and he understood he was not in a good moment.
"It was a tough decision to bring him back because we were winning and Pantilimon was doing well. But I have a good squad and I must choose between good players every week. When I told Pantilimon, he understood.
"Pantilimon was also doing well but I thought this game would be better for Joe.
"We have a squad and I have to make the decision every week who will play, not only Joe Hart."