The goalkeeper joined the Premier League champions from Malaga in the summer, but has spent the start of the season on the bench behind Joe Hart.
The Argentine told the Manchester Evening News: "It's about working hard and well for the opportunity. If not in the league, then in the cup, in whatever game, and keep trying to be ready. I need to play week-on-week and for this I think I'm ready.
"The most important thing for the player is you have one opportunity to go to the big club and Manchester City is a big club in the world at the moment. It's most important for a player to play for a title and a trophy.
"When I think of a change in club, City was a very good opportunity for me and my life and career. I worked two-and-a-half years with [Manuel] Pellegrini and it is important for the player to know the staff, the way to work, day-to-day, to prepare for the match and I think he's a really good coach."
Hart has start the majority of City's Premier League matches since taking over from Shay Given in 2010.