The two undefeated heavyweights will put their belts on the line in front of 80,000 people at Cardiff?s Principality Stadium next weekend, leaving the winner crowd WBA, IBF and WBO champion of the world.
Parker, 26, will enter the fight as the underdog, coming in off the back of a trio of underwhelming against Andy Ruiz, Razvan Cojanu and Hughie Fury ? the latter of which came on British soil in front of barely 5,000 spectators.
But despite being heavily tipped to overcome the 24-0 New Zealander, former cruiserweight king Nelson believes AJ is taking his opponent very seriously.
?Anthony Joshua and Robert McCracken have learned a harsh lesson from the Takam fight by thinking ?it?s a late substitute? so you drop your guard a little bit,? Nelson told Daily Star Online during an exclusive chat.
?The thing with this fight is, they will have done their homework no matter what.
?Yes, they will look at the Hughie Fury fight and the other fights and think ?well, these guys messed him about?. But if you get in the ring with a fighter that is hard to hit then that is how it is.
?Up to a certain point, fighters have been there for Parker to hit.
?So he has shown that he?s not unbelievably fast, he?s not unbelievably clever to be able to cut a fighter off and get rid of him ? I think Hughie Fury could actually make cruiserweight.
?To me, it shows the vulnerability or inexperience on Parker?s side at a certain level. You?ve got to go through all shapes and sizes to become a fully-rounded fighter.
?Anthony Joshua himself says, ?I?m not perfect, I?m not the finished article? because he is constantly learning.
?Part of his learning curve was fighting [Wladimir] Klitschko, part of his learning curve was the Takam fight, this will be part of his learning curve.
?It?s all in preparation for one big fight which is against Deontay Wilder.
?[Wilder] is very unorthodox, very wild, so how else can you prepare for a man that doesn?t know what he?s going to do when he steps into the ring.?
