Wladimir Klitschko and Tyson Fury go head-to-head on July 9 in Manchester, but first, there is a full-on slanging match taking place.
Klitschko responded to Fury's ongoing taunts by telling him to "f*** off" over his comments on women and homosexual people.
Klitschko attacks Fury
But now he has taken a step to wind up the well-known Manchester United fan even further - by donning a Manchester City shirt and posting the photo on Instagram.
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The Ukranian fighter will be hoping he can do his talking in the ring as he aims to regain his WBA and WBO belts, which Fury took from him in Germany last November.
However, the veteran boxer will now be the underdog. At 40-years-old, he may struggle if Fury once again takes him 12 rounds. If he loses again, it will surely be his last fight, though the British fighter has also suggested he will consider retirement if he doesn't win.
Yet, he is clearly doing everything he can to unsettle the Mancunian, who has said his biggest dream is to fight at Old Trafford.
Even if he is yet to fulfil that dream, Fury will at least have the benefit of a Manchester home crowd for the bout, though the blue half of the city might now have to reconsider who they'll be supporting on the night.
Will Tyson Fury get the better of Wladimir Klitschko? Have your say in the comments.