The deal will also see Croatia global Mateo Kovacic join Chelsea on loan for the duration of the 2018-19 season.
He is believed to have a release clause of 80m euros (£71m) in his Athletic contract, which the Premier League club are apparently willing to meet.
Thibaut Courtois is set to leave Chelsea for Real Madrid
The Blues broke the world record fee for a goalkeeper to bring the 23-year-old in from Athletic Bilbao in a deal worth £72m.
Report after report has surfaced over Courtois' exit, with stories going as far to say that a fee had been agreed between Chelsea and Real Madrid for the Belgian.
Furyk wary of Europe's 'strongest ever' Ryder Cup team
The weekend at Firestone, with as much player history as any course on TOUR, was a clinic for that sort of firepower. Players typically take the final day of practice to get in nine holes, or maybe do light work on their games.
"It's a very important decision for me, for my career, and also for my personal life", Kepa told Chelsea's website.
Courtois spent three years on loan at Atlético Madrid from Chelsea, before becoming Chelsea's No 1 in 2014-15.
I fulfilled a childhood dream playing in the Premier League, therefore I am really proud that we were able to win two Premier League titles, a League Cup and an FA cup!
Stella McCartney on the quality she shares with friend Meghan Markle
Markle celebrated her 37th birthday on Saturday at the wedding Of Prince Harry's close friend, Charlie van Straubenzee. Radar readers know Thomas has embarrassed his daughter a couple of times in the months after her wedding.
"It's an accumulation of things, and I am very glad Chelsea has chose to trust me and to take me in as well".
Meanwhile, midfielder Willian continues to be linked with a move to Manchester United and Barcelona, even though Chelsea are reluctant to sell the 29-year-old Brazilian.
Chelsea have wasted no time in showing off their latest addition, with Kovacic snapped around Stamford Bridge with the new home kit for 2018/19. As part of the deal Mateo Kovacic will join on a season-long loan'.
Google Pixel 3 leaks again with USB C Pixel Buds in tow
Google's newly-announced Android 9 Pie has a provision for developers to create apps that are compatible with a notched display. Both the front and rear camera will support Portrait mode, which Google introduced in the 2017 variants with Pixel 2 phones.