The France midfielder, who scored in Sunday's Capital One Cup final win over Sunderland, has established himself as a key member of Pellegrini's plans since the Chilean's arrival at the Etihad Stadium last summer.
Nasri has credited Pellegrini's influence for helping show his best form and claims he has shown more faith in him than former City manager Roberto Mancini.
When questioned on the difference in his performances for club and country, Nasri told L'Equipe: "It is not only on the pitch.
"It is also trust people give you. At Manchester this season, I have a perfect coach. He reminds me a lot Arsene Wenger. He really trusts me.
"Before (last season), after 50 minutes, I could see the board go up and I know it was for me to be substituted. Not anymore.
"I have a coach that always tells me I am an important player. I can feel it, my team-mates try to play with me on the pitch.
"I can feel it from the fans too. I worked to reverse the general opinion.
"Last year after the (Robin) Van Persie free-kick [in the defeat to Manchester United] I was public enemy number one.
"When there is such a rush on you, you can't be outstanding anymore.
"Trust, it is about 90 per cent of a footballer."