"I think it was a very close game. It's a difficulty that they play here with a lot of intensity at home," he said.
"I'm absolutely sure that if they play the same way in the Championship they will possibly be in the best position."
City are now battling for trophies on four fronts as they remain in the Champions League and Capital One Cup while also maintaining a Barclays Premier League title bid and Pellegrini refused to rule out bringing in reinforcements in January.
"It doesn't mean that we cannot do, maybe some things from now until the end of January but, for now, nothing important," he added.
Goalscorer Scott Dann hailed Blackburn's attacking attitude after they secured an FA Cup replay with Manchester City in their third round clash at Ewood Park.
Alvaro Negredo had given City the lead just before the break but Dann equalised and Rovers were given real hope when Dedryck Boyata was shown his second yellow card for a challenge on DJ Campbell with five minutes to play.
The home side pushed for a winner in the closing stages but Manuel Pellegrini's men held firm and the two sides will have to do it all over again at the Etihad Stadium.
"In the FA Cup, anyone can beat anyone on any day and I think we showed by the substitutions the manager made, we were positive about it, we showed we wanted to win the game and not just take a replay," Dann told BT Sport 1.
"We tried to win the game and unfortunately we couldn't quite do it.
"We knew we'd played quite well in the first half and to concede a goal like that just before half-time might have knocked the stuffing out of us.
"But we knew if we carried on doing what we were doing in the first half we were hopefully going to get something out of the game and we stuck to it and we got our reward in the end."
Manager Gary Bowyer was full of praise for his team and took particular pride in the way they responded after conceding late in the first half.
"I thought they were excellent today against a world-class City team that are capable of winning every trophy they enter this season," he said.
"We just told them to stick at it and we'd see what we were made of in the second half.
"They keep on getting better and they keep learning and they keep improving.
"Nothing but pride today.
"There's a lot of good young players there that did themselves a lot of credit today."