After being informed by Conte that his Chelsea career was over, Costa was hoping he would be able to move back to Madrid with his former club, only for their ban to be upheld.
So, just the small matter of a £24m gap and of course the whole part about what to do with Costa for the six months before he can actually play for Atléti to figure out. But, unfortunately ended up on the losing side.
Atleti are now serving a transfer ban which was upheld despite a recent appeal, meaning they can not register any new players until January 2018.
Diego Costa led the line with aplomb this past season, netting 20 goals and providing 7 assists in 35 league appearances.
His absence would also damage his chances of making the Spain squad for the 2018 World Cup.
The Brazil-born grouch looked set for China for big bucks in January but his popularity has plummeted like his pricetag and he is now available on the "cheap". He is not expected to be given a place in the first team, and would only be with the club during training.
This news will come as no surprise to fans at Stamford Bridge, as Costa hasn't been shy in expressing his desire to leave the club.
The London club signed Costa from Atletico three years ago for £32m when Jose Mourinho was manager.