Kevin Johnson: Anthony Joshua is a "grown man in a diaper"

American heavyweight Kevin Johnson has promised to "expose" Anthony Joshua when they clash at London's O2 Arena.

Joshua has won all 12 of his professional bouts inside three rounds but former world title challenger Johnson, who has never been stopped, has branded the Olympic gold medallist "a grown man in a diaper" as he looks to pull off a huge shock on Saturday night.

The 35-year-old told BBC Radio 5 live: "He's nothing but a grown man in a diaper - I will expose that to the world.

"I don't rate him at all. He has no business being on my level. His corner will either throw in the towel or he'll be stopped before they can even get their hand in the air."

Joshua's meeting with Johnson features on a card that also includes Kell Brook's IBF welterweight title clash with Frankie Gavin.