Kepa Arrizabalaga is flying to London to complete a world record £71.6m transfer from Athletic Bilbao to Chelsea.

It has been confirmed that Chelsea have paid the release clause in Arrizabalaga's contract.

The Spaniard just needs to pass a medical and agree personal terms, which are not expected to cause a problem, to finalise the switch and should be eligible to make his debut at Huddersfield on Saturday.

It means Chelsea's previous first-choice goalkeeper, Thibaut Courtois, will be able to complete a £35.5m move to Real Madrid. He is on standby to travel to the Spanish capital from Belgium, where he has been on strike to force the transfer, on Thursday.

Arrizabalaga will now replace Liverpool's new signing Alisson as the most expensive keeper in the world.

Chelsea defender David Luiz welcomed the possibility of Arrizabalaga's arrival after Tuesday's win over Lyon and believes it shows the club are still a major force in the market.

Luiz told Standard Sport: "He is a great keeper, that is why everybody is talking about him. Does this show the ambition of the club? Yes of course. Chelsea is a big club.

"The financial side - every club in the world spends money, not just Chelsea. It doesn't matter the numbers, we are happy because Chelsea are always doing the best for the club."

Chelsea made the dramatic swoop for Arrizabalaga on Tuesday having spent several weeks discussing a number of potential targets, including Kasper Schmeichel, Jordan Pickford and Jack Butland.

But Real Madrid's offer to send Matteo Kovacic on loan to Stamford Bridge helped bring about the Kepa deal and in turn secure their own transfer for Courtois.

The Blues wanted to buy another midfielder and were looking at Inter Milan's Matias Vecino, who is valued at around £32m, but funds saved on Kovacic's loan move - with an option to buy next year - and Courtois' £35.5m fee have been put to purchasing Kepa instead.

The 23-year-old is rated as one of the best young keepers in the world, although Chelsea could have bought him for just £18m seven months ago. That was the previous cost of his release clause before a transfer to Real Madrid fell through and his contract was renegotiated at Athletic Bilbao.

The Liga club made it clear to Chelsea on Tuesday when they first made their approach that they would not negotiate the cost under any circumstances.

Courtois' decision to refuse to report back for training at Chelsea this week put the club under pressure to find his replacement before Thursday's transfer deadline.

The 26-year-old, who has already agreed a six-year contract at Real Madrid, told new Chelsea boss Maurizio Sarri in a phone call last week that he had no intention of playing for the club again.

The Belgium international was bought from Genk for £7m in 2011 and has been first choice since 2014, winning four major trophies in that time.

Striker Olivier Giroud admits he is disappointed to see Courtois go. He said: "It's true that we have not seen him (in training). If he leaves it's going to be sad for us because he is a great keeper."