When Diego Costa had a reported bust-up with Antonio Conte in January, it looked as though it could derail Chelsea’s title dreams.While he was left out of Chelsea’ next Premier League fixture against Leicester, Costa was soon back in the line-up.And it appears that Costa and Conte have since put their differences aside as he helps his side go within one win of Premier League glory.Despite Costa playing, and scoring, consistently these days, the rumours of him leaving the club haven’t gone away. He’s been heavily linked with a move to China at the end of the season and it seems unlikely that he will be at Stamford Bridge come the start of next season.And Chelsea fans think they received confirmation that he will leave the club.After opening the scoring against Middlesbrough, the supporters noticed something very strange about his celebration - he started waving to the crowd.Was he simply aiming the wave at a family member or was he saying goodbye?

Costa's celebration

Take a look for yourself:

Twitter reacts

Well, the Chelsea fans on Twitter were convinced that it was a sign that Costa was definitely leaving. Check out the reaction:

Costa’s opener set the Blues on their way to a very comfortable victory, relegating Middlesbrough in the process.

Marcos Alonso soon doubled the lead before Nemanja Matic made it 3-0 in the second-half.

It means that victory against West From on Friday would see Chelsea crowned champions.

Whether Costa will be part of Conte’s side as they attempt to defend their title next season remains to be seen but it seems unlikely.