However, Chelsea boss Antonio Conte has managed to strengthen his Blues side by axing the Spain international, thanks to the arrival of Alvaro Morata.
The Italian told Costa he was no longer part of his plans this summer, brutally texting the 28-year-old the news.
Costa then went AWOL, refusing to return to Chelsea until the Blues had sorted his dream return to Atletico Madrid.
With the Blues seemingly in turmoil and Conte’s Stamford Bridge future up in the air due to tension over transfers, Chelsea had to deliver.
And in Morata, the Blues have a real superstar.
Eyebrows were raised when Chelsea splashed out £70m on the Real Madrid striker after missing out on Romelu Lukaku, who snubbed the Blues for Manchester United.
Morata was tipped to join United all summer but Jose Mourinho made sure the Red Devils landed Lukaku when given the chance.
He struggled to get game time at the Bernabeu with Real’s star-studded line up forcing him to warm the bench.
However, in limited game time, Morata still managed to net 20 goals in all competitions last season.
And the 24-year-old has hit the ground running following his move to west London, netting seven goals in as many games for Conte.
Morata’s hold-up play, decision making and all-round ability as a No.9 has taken the Premier League by storm.
The Spain international is a calming influence on the pitch, something Costa struggles to get to terms with.
And with Costa set to join Atletico in a £57m deal in January, Conte seems to have made the right decision to axe the fiery striker.
The Blues boss has swapped Costa, 28, for a younger striker who has more to offer.
Chelsea will clearly miss Costa’s grit and determination on occasions but Morata has a robust side when needed.
Costa was in the stands last night as Chelsea faced Atletico at the Wanda Metropolitano in the Champions League, with Morata and Michy Batshuayi netting to sink Diego Simeone’s men in Madrid.
Many would have excused Morata for having an off-night against Atletico.
The Spanish fans booed and jeered the striker all game due to his Real links, as well as having the Chelsea star he replaced in the stands watching on.
However, the former Juventus man rose to the occasion and silenced the Atletico faithful, netting the first away goal at their new stadium.
Eden Hazard’s pin-point cross was nodded home by Morata on the hour mark, his fourth headed goal of the season.
Blues winger Hazard made his first start of the season against Atletico and it became clear quickly that Morata became even better in the presence of the Belgium international.
Hazard played in a front two with the ex-Real man and bullied Simeone’s back four.
Their link-up play was too quick for the Spanish giants, with Hazard working off Morata all night.
Hazard takes attention away from Morata, with the playmaker finding space in-between the lines to help the Chelsea hitman.
Conte took a huge risk by telling Costa to leave this summer but in Morata, Chelsea need not worry about missing their lovable rogue.
