Top 10 controversies of 2017

#7 The Conte-Costa Controversy

Diego Costa left for Atletico Madrid following a feud with Antonio Conte this summer

Spanish striker Diego Costa was the spearhead as Chelsea hustled to win back the Premier League title from Manchester City in 2017. However, few could have predicted the ways in which he said goodbye to the club.

Antonio Conte had already made up his mind on selling the player back in January this year, given his increasingly edgy behaviour at the club. Things took a turn for the worse when Costa refused to be a part of the training sessions in Chelsea's pre-season tour.

Further fanning the fire, the Spaniard revealed a message Conte had sent him.

Hi Diego, I hope you are well. Thanks for the season we spent together. Good luck for the next year but you are not in my plan.’

The texted message proved to be the final nail in the coffin of the striker's relationship with the manager.

Costa also claimed that he was treated like a criminal; a statement to which Antonio Conte burst out with hysterical laughter in a press conference. Apparently, what angered the striker was the way in which the Chelsea boss axed him - with a message on a phone instead of having a face-to-face talk.

In the aftermath, he secured a move back to Atletico Madrid but was ineligible to play for them, given their transfer ban until 2018. He will start playing regularly from January.

Chelsea brought Alvaro Morata as a replacement for him, but there's no doubt the Blues still miss the brilliance of the 29-year-old.