By Keith Idec

Joseph Parker has not been knocked down as an amateur or as a professional boxer.

The unbeaten WBO heavyweight champion realizes that could change when he encounters one of the two biggest punchers in his division March 31 at Principality Stadium in Cardiff, Wales. England’s Anthony Joshua has knocked out each of the 20 opponents he has faced since he turned pro, a daunting fact that isn’t lost on the 26-year-old Parker (24-0, 18 KOs).

The 6-feet-4, 245-pound Parker made it clear upon arriving in London, however, that he believes he can knock off the British superstar in a title unification fight that was officially announced Sunday.

“I’m not scared of AJ,” Parker told Sky Sports in an interview made available on its website Sunday. “I know he’s a good fighter and I respect him, but I back myself with anyone I jump in the ring with. I’m looking forward to putting on a great show. I don’t care if I win or lose. I just want a challenge and I think there should be one champion.”

Parker pointed to Joshua getting knocked down by former champion Wladimir Klitschko (64-5, 53 KOs) during their unforgettable fight April 29 as a reason he can win. Joshua, 28, got up from that sixth-round knockdown, got a second wind, dropped the 41-year-old Klitschko twice more in the 11th round and won by technical knockout at a sold-out Wembley Stadium in London.

Each of Parker’s three WBO heavyweight title fights have gone the distance, but the Auckland, New Zealand, native cannot envision any scenario in which his battle against the 6-feet-6, 250-pound Joshua doesn’t end in a knockout.

“I know he’s been down,” Parker said when asked about stating that Joshua has a glass chin. “Glass chin is just one of those things where my team, we came up with to describe him and what his chin is, but I feel like I have a lot of respect for him.

“In the last fight I saw with [Wladimir] Klitschko, he got knocked down, got up and showed a lot of heart, so credit to him. But I think when we come together, we’re both going to throw some big bombs and someone is going to get knocked out.”

Keith Idec is a senior writer/columnist for BoxingScene.com. He can be reached on Twitter @Idecboxing.