The countdown has begun for Anthony Joshua's heavyweight title fight with Wladimir Klitschko.

In eight days' time, the pair will meet in front of a record-breaking audience at Wembley Stadium to battle it out for the IBF and WBA titles.

Joshua is bookies' favourite ahead of the bout at 2/5, with the 27-year-old's record of 18-0 - all of which KOs - also on the line.

However, claiming the WBA Super title has its complications for Joshua. Should he beat Klitschko, he may have to vacate his IBF heavyweight world title.

Both sanctioning bodies would want the winner to fulfil a defence of their titles, which might not be possible, as Eddie Hearn recently explained.

"If AJ wins, you're going to get the problem of multiple mandatories coming up," he said, per the Mirror. "So after this fight, AJ's mandatory is [Kubrat] Pulev with the IBF.

"At some point, maybe not next, but probably this year, the WBA mandatory is Luis Ortiz. It's quite possible he will have to vacate unless a deal can be done.

"I'd love him to have all the belts, but as Tyson Fury found out, that's not really possible."

Back in 2015, Tyson Fury was forced to vacate the IBF heavyweight title after winning it from Klitschko because he couldn't fulfil the mandatory.

That thought will be far from Joshua's mind at the moment, of course, especially so when there's scope for a rematch with Klitschko - yes, you've read that right.

According to the Times, Joshua and Klitschko have a rematch clause in their contract that either boxer can activate after their fight.

No further details have yet been provided, but it's understood both parties wanted the option to have a rematch in the event of defeat.

But while a rematch would make sense financially, doubts remains over whether Klitschko, now 41, would want to fight Joshua again - not unless he gets demolished.

And that could well end up being the case if Joshua follows through with his threat of going for the knockout next weekend.

"I'm going for the knockout, that's what I do," he said during 'The Gloves Are Off'. "I haven't experienced losing as a professional yet so I don't know that feeling.

"I'm going for a knockout. I always say you either crumble or rise to the occasion. I'm conditioning my mind talking about it, visualising to make it into reality."