The Spain international endured a nightmare second half to the 2012-13 campaign, failing to start a game from February onwards after being relegated to the bench by then-coach Jose Mourinho.
The pair reportedly shared a fractious relationship during Mourinho's time at the club, which further soured when Casillas failed to oust Diego Lopez from the first team following his recovery from a hand injury.
But with the arrival of new manager Carlo Ancelotti offering the 32-year-old a chance to return to first-team action, he has underlined his desire to work hard than ever to make sure that is the case.
"I would love to be a starter again. I work and compete for it, even though my team-mates do the same," he said. "Everybody starts from scratch, but I have much more enthusiasm to get there than before.
"I know that my team-mates are going to make it difficult. I am going to work to get into Carlo's team. There is a lot of competition but I am going to work, to fight and struggle, like I have done all my life, with the idea of regaining my place.
"To return to training to compete, to fight, and I hope to be happy. Later, the manager will decide.
"It is a new hope and a new challenge. This club needs wins and titles and we must get them. Last season we were close to winning titles, now we are more eager to begin obtaining the goals that we have set ourselves in the three competitions that we are in."
Casillas also insisted he is by no means certain to replace January arrival Lopez from the starting XI, adding: "Not in any way, but I have a desire to compete (with him). That is good for a player. Competition is healthy.
"All of my team-mates are great goalkeepers and they have shown it before. Diego was sensational last year. You must live with that competition.
"We have two or three players for each position and that is positive. I am at the manager's call when I get an opportunity."
The 148-times capped Spain captain went on to comment on Real's public pursuit of Tottenham star Gareth Bale, lauding the winger as one of Europe's top talents.
"(He is) one of the three or four best players in Europe," he added.
"All transfers are controversial, for better or for worse, but he is a very decisive player and is very good.
"The club are going to be in charge of trying to improve our good position. It is the summer and there will probably be more signings."
