Romanian understudy Costel Pantilimon, who played in the 2-0 League Cup win over Newcastle United on Wednesday, retained his place in the starting lineup for his first Premier League appearance and kept a clean sheet in a 7-0 victory.
"My duty is to see every week who is the best player to play," Pellegrini was quoted as saying on the City website (www.mcfc.co.uk).
"Joe needed a rest, it will be useful for him - he's played every match for two years. Every player can have a bad moment.
"I only know that Joe must work very hard and he will have all of the support of me and the goalkeeper coach and the team. He is England's goalkeeper and I think he will be back.
"I am sure he will return to his normal performance."
Hart's run of errors continued last Sunday when he was involved in a mix-up with defender Matija Nastasic that allowed Fernando Torres to score a late goal and give Chelsea a 2-1 win over City at Stamford Bridge.
Pantilimon's only appearances for City last season and this had been in cup matches before Saturday.
Image: Joe Hart
Photograph: Nigel Roddis/Reuters
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