Diego Costa has completed his move from Chelsea to Atletico Madrid, the Spanish side have announced.
The 28-year-old striker has initially signed on loan until the end of the season, although Atletico’s transfer embargo means he cannot play until January.
Costa, who has scored 59 goals in 120 games for Chelsea – twice winning the Premier League title – will then join Atletico for a reported fee of £58million.
Atletico and Chelsea announced an agreement had been reached last Thursday and it has now been completed on the eve of the teams’ Champions League Group C contest at the Estadio Wanda Metropolitano.
Costa said on Atletico’s website: “I’m very happy to return home, I’ve always said it, Atletico is my home, I’m very, very happy.”
The Brazil-born Spain striker’s time at Chelsea ended in claim, counter claim and acrimony.
He expressed his gratitude to Atletico for making the move, which will be officially registered on January 1, 2018.
He said: “I’m looking forward to start contributing. I’m going to give my all for the team, as I always try to do.
“I’m very grateful to everyone… the whole club for making this move forward.”
Chelsea reflected on Costa’s three years at Stamford Bridge following his July 2014 arrival from Atletico for £32m.
And the Premier League champions signed off the message by saying: “We thank Diego for his efforts and wish him well in his future career.”
Atletico coach Diego Simeone had earlier declined to discuss Costa at his pre-match media conference.
Simeone and midfielder Koke did praise Alvaro Morata, Costa’s replacement at Chelsea.
Koke said: “Morata struggled a bit at first, but now he’s adapted and everything he touches flies into the net.
“Let’s hope we can control him better tomorrow.”
Atletico had a formidable record at their former home, the Vicente Calderon Stadium, winning 30 of their last 36 European fixtures there, losing only twice. They are unbeaten against European opposition.
Simeone’s side advanced to the 2014 Champions League final at the expense of Jose Mourinho’s Chelsea before losing to city rivals Real in Lisbon.
“It’s a very different team to the side we met in 2014,” Simeone said.
“I love the kind of game they play, the intensity, the balance, the collective work rate in defence and knowing what they need to do on the pitch.
“That helped them win the Premier League last season. They’re a very tough team with a very good manager who has instilled his personality in the team.”
Chelsea opened with a 6-0 win over Qarabag of Azerbaijan as Atletico drew 0-0 at Roma.
Midfielder Koke said: “This won’t necessarily be the match to decide who wins the group, but it will be important.”