LONDON • Chelsea manager Maurizio Sarri has praised Kepa Arrizabalaga as the Blues smashed the world record fee for a goalkeeper to replace Thibaut Courtois, who is expected to sign for Real Madrid.

Spanish and English media reported that the Athletic Bilbao No. 1 was in London yesterday to complete a medical test and his move. With funds from Chelsea, he had paid the €80 million (£71.6 million, S$126 million) needed to trigger the buyout clause.

In Spain, instead of the buying club paying the selling club the amount set by the contract, the player must buy himself out. This is done by depositing the amount of the buyout clause with LaLiga to release a player. LaLiga then passes the money on to the selling club.

The Spanish international, 23, had yet to sign by press time but he would become the world's most expensive stopper ahead of Liverpool's Alisson, who cost €75 million from Roma last month.

"I saw (Kepa) one year ago when I was at Napoli," Sarri said on Tuesday after a 0-0 draw with Lyon in a pre-season friendly at Stamford Bridge. "My first impression was that he is a very good goalkeeper, very young but very good."

The 1.86m Kepa has made only one Spain appearance but he is considered one of the most promising goalkeepers in Europe, having impressed for his country through the junior age groups.

Bilbao had come close to selling the player - who joined the club at the age of 10 and made 53 LaLiga appearances over two seasons for them - to Real for only £17.9 million in January.

He even passed a medical test in the mid-season window only for then-Real manager Zinedine Zidane to dissuade the board from pursuing a deal as he was wary of disrupting the team's rhythm with a goalkeeping change halfway through the campaign.

Bilbao ended up tying him down to new terms, including the eye-catching buyout clause, before finishing 16th. Kepa is expected to make his debut in Chelsea's Premier League opener at Huddersfield on Saturday if he signs in time.

The move still constitutes a surprise, not least because Chelsea, too, looked into signing Alisson earlier this summer but were apparently put off by the size of the fee.

But the Blues, who had also considered cheaper options such as Jack Butland of Stoke and Sergio Rico of Sevilla, have more leeway on the Kepa fee - given their desire to add another body in midfield is close to being resolved with the signing of Real's Mateo Kovacic on loan.

The unsettled Croatian midfielder is the Spanish club's sweetener to ensure their pursuit of Courtois reaches a positive conclusion. Kovacic has made clear a desire to play more regularly and will be permitted to leave for the season.

But Chelsea would not have an option to make the move permanent next summer, with Real considering him a long-term successor for his compatriot, Luka Modric.

Courtois, meanwhile, is expected to join Real for €35 million.

Chelsea are hoping to recover after a disappointing EPL title defence last season saw them finish fifth.

REUTERS, THE GUARDIAN, AGENCE FRANCE-PRESSE