The striker is on-loan at Inter this season from Lazio.
"I am grateful to Claudio Ranieri, because he has so far given me the opportunity to play and I think I am also proving I am eager to learn and become a great player - a player worthy of Inter," said Zarate.
"I really want to become the kind of striker who can play in more than one role and be strong in any position, both at club and international level.
"I wanted to do so much more in the first few months of my Inter career, so I am disappointed. I think everyone can see I work hard to improve day after day and always give my best.
"If you are in a team like this, how can anyone feel they are automatic first choices? No, I think we are all ready to help and fight for the common good.
"This weekend we have to win against Siena. We need a series of good performances and five or six victories on the bounce to climb up the table. We will do it."