Boxing fans have now come to terms with the fact that it's Alexander Povetkin who will be fighting Anthony Joshua at Wembley on September 22.The Russian may be 38-years-old but his impressive record of 34-1 - with 24 of those victories coming via knockout - still makes him a formidable opponent.Besides, his status as the WBA's mandatory challenger meant the current three-belt heavyweight champion had little choice but to take him on.On Tuesday, Povetkin ought to have been in the spotlight at his first face-off with the British fighter in New York.Instead, Joshua was more than a little distracted by the presence of foe Jarrell Miller on stage and the pair became involved in a heated exchange, with Eddie Hearn stepping in between them.Footage made it very hard to hear what was said - with much of the strong language inevitably blanked out - yet the Telegraph claim Joshua shouted:“Who you f***ing talking to, shut the f*** up and get off the stage, you little b***. I'll slap you. Have some respect.”There is considerable tension there because the American considers himself a viable contender to challenge the 2012 Olympic gold medallist and wants to make a fight happen.As he focuses on Povetkin and beyond that, Deontay Wilder, Joshua has been dismissive of Miller and followed that trend by tweeting a message to him after their clash.

AJ has a warning for Miller 

The 28-year-old posted:

"Massive respect to Povetkin. When two lions meet & you hear a lil pup barking, don’t play with big cats... That’s a warning."

Inevitably, that is only going to stir things up all the more and the 'Big Baby' won't have been warned off one bit.

The next couple of years are ultimately going to make or break Joshua's reputation amid discussion of whether he can ever really count himself among the great heavyweights unless he fights the very best that's out there - and even then, the past couple of decades haven't been the best for the division.

Starting with Povetkin, who is four inches shorter, AJ has a chance to make a statement.

If he wins that fight and if his team fail to reach a breakthrough in the Wilder talks, many would no doubt like to see him get in the ring with Miller next. 

Would Miller have any chance against AJ? Have your say in the comments.