Casillas lost his place in the Real Madrid starting line-up last season. [Reuters]

Iker Casillas has reportedly asked Real Madrid officials to let him go as a free-agent in order to facilitate a summer move away – with Arsenal in pole position to secure his services.

The Spaniard's future at the Santiago Bernabeu has been under increasing scrutiny since Jose Mourinho benched him two seasons ago in favour of Diego Lopez.

He was expected to regain a place in the starting line-up with Carlo Ancelotti but the Italian manager eventually kept Lopez as his preferred choice in La Liga, with Casillas playing only the Champions League and the Copa del Rey.

And even though the 33-year-old won both tournaments, he has been questioned after committing a serious error in the Champions League final victory over Atletico Madrid.

Speculations about his future increased this week after Real Madrid reportedly signed World Cup sensation Keylor Navas – meaning either Casillas or Diego Lopez has to leave the team to make a vacant for the new keeper.

While Lopez's agent recently said his client is likely to stay, El Confidencial claims Casillas wants a summer move away.

Indeed, the Spanish newspaper claims the Spaniard has asked Real Madrid to release his current contract in order to become a free-agent and facilitate his exit.

El Confidencial reports that a number of big clubs are monitoring the situation but Arsenal are the main candidate to secure his services, as Casillas is reportedly keen to experience playing in the Premier League, especially in London.

Arsene Wenger has been reportedly interested in Casillas in recent months. According to El Confidencial, Wenger understands that even though Arsenal cannot afford his huge salary, they will be able to sign him should he become as a free-agent.

Earlier this season, Santi Cazorla revealed he had advised Casillas to join him at the Emirates Stadium this summer.

"I've told him [I would like him to join Arsenal] but so far he has just been curious about my experience in England," said Cazorla.

"His situation is very complicated but he has to make a decision. Lots of clubs want him, including Arsenal, but I think it would be very difficult to leave Real Madrid because of what the club represents. He knows what he has [at Madrid] and what he could find at another club."