When Wladimir Klitschko recently announced his retirement from the sport, it caught a lot of people by surprise.

Many had expected Klitschko to at least go forward with a planned rematch against WBA, IBO, IBF heavyweight champion Anthony Joshua.

Back in April before a crowd of 90,000 at Wembley, the two fighters engaged in one of the best heavyweight contests in recent memory. Klitschko survived a knockdown in the fifth round to rally hard and have Joshua on unsteady legs by the end of the same round. He then dropped Joshua and hand him in serious trouble during the sixth. Joshua eventually came back in the championship rounds to score two more knockdowns of his own to stop Klitschko in the eleventh.

There was a rematch clause in place and there were already moves being made to set down the second fight.

A few weeks ago, Joshua's promoter Eddie Hearn had flown over to Las Vegas to take a tour of the T-Mobile Arena - which was likely going to host the second fight on a date in November.

Joshua, who owed a mandatory defense to the IBF, had even received permission from the sanctioning body to face Klitschko in the fall.

After some careful consideration, the 41 year Klitschko felt 'enough was enough' and he was not swayed by the possibility of earning a huge payday in a final career bout.

"I had thousands of reasons to agree to a rematch and the same number of reasons to finish my career, but at the time of [making] the decision - a part of me was already dead, I noticed that the motivation was not at that level, even the possible $20 million that I could earn for the rematch with Joshua.. could not change my opinion. If I continued to fight only because of the money, I would be deceiving myself," Klitschko said.