Kiko Casilla
Kiko Casilla has garnered a reputation as one of the best Spanish keepers during his time at Espanyol Getty

Real Madrid have signed Espanyol goalkeeper Kiko Casilla amid delays in the negotiations to lure David de Gea from Manchester United and the expected departure of Iker Casillas to Porto, according to Spanish radio station Cadena Cope.

Paco Gonzalez, one of the most reliable journalists regarding Real Madrid, broke the surprising news on Tuesday night (7 July) after assuring Los Blancos have already agreed to pay Espanyol around €3m (£2.1m, $3.3m) to secure the services of Casilla – with the deal expected to be official before the end of this week.

More about Manchester United

Casilla, 28, grew in the Real Madrid ranks before moving to Espanyol where he has garnered a reputation as one of the best keepers in Spain, being recently included by Vicente Del Bosque in the national team squad as the third choice to back-up Iker Casillas and De Gea.

Gonzalez says Casilla's imminent move to the Santiago Bernabeu doesn't mean Real Madrid have given up in their intentions to sign De Gea, but it is a clear message to Manchester United that if they keep stalling on the sale of the Spaniard, they already have a back-up.

Rafa Benitez's side had earmarked the signing of De Gea as a top priority for the summer transfer window, hoping to part ways with Casillas to hand the United star the number one role and leaving Keylor Navas as his back-up.

But Cadena Cope suggests that the delay in signing De Gea and the injury of Navas have forced Real Madrid to make an unexpected move for Casilla, otherwise new manager Benitez risks starting pre-season on Friday 10 July without a keeper available.

Casillas is indeed in advanced negotiations to leave the Santiago Bernabeu to join Porto after the agent of the club captain, Carlos Cutropia, confirmed earlier this week the Spanish legend is attracted by the chance of moving to the Portuguese giants.

One way or another Casilla move to the Bernabeu may bring a new dilemma to Benitez, who if he secures De Gea, will have three competitive stoppers in the United keeper himself, Casilla and Navas.

Cope hints that should De Gea finally come to Real Madrid, the club may consider a cash-in with Navas or to resell Casillas as the Espanyol keeper will only cost them €3m.