Iker Casillas
Iker Casillas is currently the number one both at Real Madrid and for SpainGetty Images

Real Madrid star Iker Casillas has insisted he will welcome David de Gea should the Manchester United keeper finally move to the Santiago Bernabeu this summer but alerting his compatriot that he will have to battle with him for the number-one spot.

Being out of contract at Old Trafford in summer 2016, De Gea has been heavily linked with a move to the Champions League winners in recent weeks.

Louis van Gaal recently all but admitted the La Liga giants are interested in securing his services, while reports in Spain claimed the keeper has eventually already agreed personal terms to join Real Madrid.

Casillas was expected to leave the club after falling out of favour with his own supporters to make space for De Gea.

But the Real Madrid legend has instead decided to stay at the club until the end of his contract in summer 2017 and is ready to battle with De Gea for the number one role as they already do in the national team, where Casillas currently remains as the first choice.

"If De Gea does come here, he'll be welcomed. Competition is healthy. There is not a clause in my contract which states that I have to be the number one; we'll have to compete for a place like we do with Spain," Casillas said during an interview with Spanish radio station Cadena Ser.

"De Gea is a great bloke and a goalkeeper for the present and the future. He can handle pressure and the experience he has had at Manchester United will have served him well."

"[President] Florentino [Perez] once asked me if it were up to me, which keeper would I sign. I prefer Spanish keepers: Sergio Rico, Asenjo and De Gea. Right now, De Gea is the expert out of the three."

Even though some reports have linked him with a move to Arsenal in recent times, Casillas has insisted his main choice is to hang his boot at his childhood side, and that should he have to leave, he will move to a minor league.

"I'm sure I'll continue here next season – of course. I cannot imagine myself outside of the club when the new campaign starts. I want to end my career here," the keeper said."

"But there's always the chance that I could go to a smaller league; if things don't turn out and I have to leave, but right now I see myself as being strong and up to the job in hand. I'll confront next season as though it is my first; that's the challenge I've set myself."