Diego Costa arrived in Spain on Friday as the striker closed in on his return to Atletico Madrid from Chelsea.
The Premier League champions on Thursday confirmed they had agreed terms with Atletico for the sale of the Brazilian-born Spain international for a fee that could reportedly rise to EUR60million.
Costa will not be able to play for Diego Simeone's team until January as Atletico serve a FIFA-imposed player registration ban.
But, having succeeded in forcing through his departure from Stamford Bridge, Costa landed in the Spanish capital to undergo a medical.
Atléticos, a friend says hi! pic.twitter.com/l9AzyL9ou8-- Atlético de Madrid (@atletienglish) September 22, 2017
The centre-forward moved to the Blues after helping Atletico to win LaLiga in 2013-14 and proved equally effective in the Premier League, Chelsea capturing the title in Costa's first season in England and again last term.
However, Costa fell out with manager Antonio Conte amid speculation linking the 28-year-old with a move to the Chinese Super League.
Costa had been in Brazil since July and has refused to return to Chelsea training, accusing the club of treating him "like a criminal".
Conte laughed off the comments and said he would not pick the striker even if he made himself available, having signed Alvaro Morata from Real Madrid for a club-record fee to become his first-choice forward.