Casilla, 27, has established himself as the first choice for Espanyol over the last two seasons, and has performed consistently for Javier Aguirre's men, but those impressive displays have attracted the interest of a number of clubs in Spain and around Europe.
Arsenal, Manchester United, Barcelona and Real Madrid have all been linked with swoops for Casilla, but all those teams - and no doubt a host of others - look set to be disappointed, as the highly regarded shot stopper has vowed to stay with Espanyol until at least the expiration of his contract, which runs out in 2015.
"I have one year left of my contract and I always keep what I have signed," he said. "In addition, the renewal will be arranged. At Espanyol I am playing and enjoying it. Here I feel very comfortable and I have always said that I want to stay.
"I do not know much about the renewal nor do I want to know until it is all done. My role is to be focused on the job and contribute my bit to the team. I insist that I will play here next year," added Casilla.
Arsenal had been linked with a move for Casilla as competition for first choice Wojciech Szczesny, with his compatriot Lukasz Fabianski set to leave the Emirates Stadium at the end of the season. It also seems that the other aforementioned clubs had a similar idea, with Manchester United, Barcelona and Real Madrid already having established goalkeepers in David de Gea, the impending Marc Andre-Ter Stegen and Diego Lopez or Iker Casillas respectively.
With that in mind, it seems Casilla is making the right decision to stay with Espanyol for the near future, as first-team football at one of his potential suitors looks like a difficult challenge right now.