The Ivorian midfielder scored his fifth goal of the campaign on Tuesday night as City hammered Wigan Athletic 5-0 in the third round of the Capital One Cup.
"He is a very important player for the team," Sky Sports News quotes Pellegrini as saying.
"I don't know what happened last year but all the players are playing with trust and a goal always give them trust. I think it is very important. He is really in a good moment."
City continue their Premier League campaign on Saturday when they face Aston Villa at Villa Park.