Real ended a stellar year by beating San Lorenzo 2-0 to claim the Club World Cup in Marrakech on Saturday.
The Spanish giants also won the UEFA Champions League, Copa del Rey and Supercopa de Espana in a memorable 2014.
Club captain Casillas has endured a mixed year, as he made only two La Liga appearances for Carlo Ancelotti's side last season and was guilty of making mistakes for both club and country.
Casillas' future at Santiago Bernabeu has been called into question, with the likes of Liverpool and Arsenal linked with a move for Real's long-serving keeper.
Casillas is quoted as saying in Marca: "It's been my best year. Four titles and I played in all of them, it doesn't get much better than that. I can't forget those things just because I had a bad six weeks.
"Let's take things one step at a time. I'm under contract and have no reason to think about leaving."
