'How can you do that': All Blacks great blasts Raelene Castle criticism

Test great John Kirwan has backed Rugby Australia boss Raelene Castle despite criticism from former Wallabies' legends. (Getty Images)

Test great John Kirwan has denounced the ex-Wallabies calling for the head of Rugby Australia boss Raelene Castle, saying former All Blacks would never air dirty laundry in public.

Kirwan also launched a fierce defence of Kiwi compatriot Castle, saying 17 years of ongoing mismanagement is to blame for RA's teetering financial state.

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Former Wallabies Rod Kafer and Nick Farr-Jones have been critical of Castle in the past week since the chief executive revealed the chasm the organisation finds itself in.

A group of former Wallabies are reportedly agitating for change, with Phil Kearns believed to be a favoured replacement as CEO. Former Wallabies captain Kearns has denied having designs on the top spot.

Ex-All Blacks winger Kirwan said he could barely fathom why a sport would want to overthrow its boss while the impact of the coronavirus pandemic is so acute.

"They should be working together. As ex-All Blacks, we very rarely go outside with our criticism before we've said it inside," Kirwan told Sky TV's Breakdown program.

"Getting attacked by so many people, it must be a pretty lonely place for her.

"Some of these famous ex-Wallabies maybe need to knock on her door or have a Zoom, and just say 'these are my concerns and these are my solutions'."

New Zealand's former rugby player John Kirwan delivers a speech during the New Zealand national rugby union team's pre-camp announcement. (Photo by Toshifumi KITAMURA / AFP)

Union’s decline in Aus: Kirwan

Kirwan said blaming Castle was a "cop-out" given the gradual deterioration of the sport in Australia since 2003, when it reaped enormous revenue by staging the Rugby World Cup after cutting New Zealand out of the co-hosting.

That was also the last year Australia held the Bledisloe Cup.

"I know we're going a long way back but they were one of the wealthiest unions in the world," Kirwan said.

"What has happened to the development of the game, for the game as a whole?

"We're seeing Waratahs teams that don't have a strong bench. There's a whole lot wrong."

Castle has come under intense scrutiny over her handling of the Israel Folau affair which played a big part in a heavy financial loss for 2019.

Kirwan believed she handled a delicate situation as well as possible and her experienced leadership would be needed to ride out the ravages of Covid-19.

"How can you even be talking about sacking your CEO during a world crisis? I don't even get that," he said.

"We need our Australian brothers, we need Australian rugby really strong."