Mario Stanić was the first, followed by goalkeeper Matej Delač, striker Stipe Perica, and offensive midfielder Marijo Pašalić, though they have all been sent out on loan from The Blues.
At 80 million euros, Arrizabalaga will become the most expensive goalkeeper in football history, ahead of Liverpool's Alisson Becker, who moved from AS Roma for 75 million euros earlier in the transfer window.
He is now in his home country and barring any more surprises, will move to Real Madrid before tomorrow's 5pm transfer deadline for a fee of around £35m.
Arrizabalaga has played 53 La Liga matches for Athletic Bilbao since breaking into the team in 2016.
Hamas fires rockets, Israel bombs Gaza despite talk of truce
The Gaza Health Ministry say pregnant 23-year-old Enas Khammash and her 18-month daughter were killed in Jafarawi in central Gaza. One vehicle was hit, the IDF Spokesman's Unit said; IDF tanks responded by attacking a Hamas position in the region.
"On Wednesday 8 August, 2018, at 12:02 hours, the Spanish Football League [LFP] has certified to our club that player Kepa Arrizabalaga has complied with the requirements to end unilaterally his contract that linked him with Athletic Club", a statement issued by Athletic read.
Athletic, all along, were only expected to sell should Kepa's buy-out clause be matched.
Mamiko Higa falls into fourth place at Women's British Open
She birdied the third, sixth, eighth, and 11th holes, and dropped her first shot of the major on the par-3 12th, a bogey. Home favourite Georgia Hall shot a near-perfect five under par final round to claim the Women's British Open title.
The 23-year-old has signed a seven-year contract with the English giants.
The 26-year-old appeared unwilling to wait a further 12 months to grant his move with Sarri publicly telling Courtois to confront him personally if he wishes to leave the club.
Bizarre, Glowing Rogue Planet Found Lurking Outside The Solar System
Brown dwarfs are failed stars-objects much larger than most planets but too small to sustain fusion reactions. Auroras on Earth are created when charged particles from the Sun interact with Earth's magnetic field.