Parker vs Joshua: Former All Blacks captain Richie McCaw backing Kiwi to deliver in Cardiff

Former All Blacks captain Richie McCaw is throwing his support behind Joseph Parker ahead of his world title fight against Anthony Joshua.

Unbeaten heavyweight boxing champions Parker and Joshua will unify their WBO, WBA, IBF and IBO belts at the Principality Stadium in Cardiff on Sunday (NZ time).

Speaking to Sky Sports UK, McCaw said he couldn't wait to see how the fight plays out at a venue where McCaw has played at numerous times.

"Like most Kiwis I'm pretty interested in what's going to happen this weekend with Joseph Parker and Anthony Joshua," McCaw told Sky Sports UK.

"I think most Kiwis will be stuck in front of their screens watching.

"I have had the privilege of meeting him a couple of times... hell of a nice guy, so softly spoken and that.

"We have got our fingers crossed for him because he's up against it."

McCaw said he was in awe of what both Parker and Joshua will be doing in the ring, putting everything on the line in an attempt to become undisputed heavyweight champion.

"Going into the ring with those guys..." he said, shaking his head. "But that's what the sport's about. Even just to get a chance to fight like that is a massive thing."

When he was told there could be up to 20 current and former All Blacks going over to Cardiff for the fight, he laughed, "I must have missed the cut".