Undefeated American heavyweight Jarrell 'Big Baby' Miller says he is unimpressed with Anthony Joshua.

The 29-year old Brooklyn native says he has analysed IBF, WBA and IBO champion's behaviour and sees an opportunity to stop him.

"What I have seen, heard, and the way he fights, he's a mental midget," Miller said, "Once I get there I'm shutting that down."

Miller made the comments in the aftermath of Joshua's 10th round stoppage win over lacklustre challenger Carlos Takam.

"I can drown him in any round. I can drown him in the beginning, I can drown him later. It don't even matter. Takam wasn't even pushing the pace and he was getting tired.

"Imagine another heavyweight that is pushing the pace, and landing shots, who is bigger than him. It's a whole different animal.

"There's a lot of things when you put two big guys in there, and the other guy does not have the mental fortitude for that. He's never been built for that."

Miller is set for this 20th boxing bout this weekend at the Nassau Coliseum in New York.

For this fight, he has been working closely with Joshua's promoter Eddie Hearn. Hearn's even been retweeting some of Miller's content. It's likely this cooperation puts Miller in the running for a future fight with Joshua, if Miller can raise his profile.

"Eventually when the time comes, he's [Hearn] talked about matching us in the middle of next year, or maybe the early part of next year.

"We've just got to build my portfolio and get everything going the right way, which I definitely agree with.

Miller, who also has an impressive record in kickboxing, weighs in at a huge 299 pounds (136kg). That's a hefty weight above AJ, who stepped into the ring against Takam at 254 pounds (115kg) a career high for the 28-year-old.

But Miller says Joshua's muscle-bound weight gain puts the former Olympian at a disadvantage: 

"First of all, he's not a natural big guy. He started as a pro in the mid-220s. Now all of a sudden, he's 254, he's four pounds heavier than he was when he fought Wladimir Klitschko and he's a lot slower.

"His footwork is horrible. It's definitely affecting his performance, his stamina is not getting any better than the Klitschko fight, even with the muscle he's putting on.

"I hope he keeps putting on muscle. By the time he fights me, then all I've got to do is move on him, tire him out, and then knock him out. It's a matter of time."

He's not mistaken to make that assessment. Pundits have commented on the possible disadvantages to Joshua's sculptured bulk since the Dillian Whyte fight.

Still undefeated, and with a win over Klitschko to boot, Joshua's physique has not slowed him down yet. Still, it could happen.

Former super champ Wladimir Klitschko suffered a loss to Lamon Brewster in 2004. Many attribute that loss to Klitschko's bulk. The Ukrainian then returned to rule the division for a decade as the paired down Klitschko we know today. 

Who do you think is the best heavyweight fighter in the division? Have your say in the comments section below.