The England international was dropped in favour of Costel Pantilimon late last year before eventually regaining his place in City's starting XI.
With the FIFA World Cup on the horizon, there had been initial fears that Hart may lose his starting spot for England, although the Chilean feels the goalkeeper displayed his professionalism to recover his place at City.
The 27-year-old has been in impressive form of late, making some crucial stops to keep City in the hunt for the Premier League - something that has not gone unnoticed by Pellegrini.
"The second round of (the season) for Joe has been a very good performance," TheManchester Evening News quotes him as saying.
"One of the good things that we did this year was to talk to him and sit him (out) some games because he was in a very bad moment but he reacted as a professional player, the number one in England."
City are now back in pole position for the Premier League title - leading Liverpool by goal difference despite defeat at Anfield last month.
Pellegrini's men then dropped points against Sunderland but have won all three games since then and the Chilean feels the point against Gus Poyet's side may not be as disastrous as first suggested.
"After we lost against Liverpool I think we had to play against Sunderland three days and everyone thought Sunderland was a very easy team," he added.
"But (they are) not so easy as they beat Chelsea and now they beat Manchester United.
"So there are merits in the draw at our stadium."
Bizarre Jose Mourinho statement aims to pre-empt punishment after Fenerbahce boss clashes with Galatasaray counterpart
'Andy Robertson has a decision to make as a player, where you either roll your sleeves up and give someone great competition or you accept decisions and say that your time is done.' Alan Shearer on the conundrum facing Arne Slot's Liverpool
