Australia boss Castle defends Wallabies coaching shake-up

MELBOURNE, Oct 22 (Reuters) - Rugby Australia (RA) boss Raelene Castle has defended the governing body's decision to shake up the Wallabies backroom staff less than a year from the World Cup, in the wake of a stinging rebuke from outgoing coach Michael Cheika.

Cheika, who announced his resignation on Sunday following the Wallabies quarter-final exit from Japan, said he had "no relationship" with Castle and was scathing of RA's appointment of Director of Rugby Scott Johnson to oversee his work.

RA also appointed Johnson as a selector on a three-man panel including Cheika and Michael O'Connor, while firing assistant coach Stephen Larkham in December at the end of the Wallabies' worst season in decades.

"I think we had to make those changes," Castle told Australian broadcaster Fox Sports.

"If you look at the results we'd had previous to that, there was a situation where a 50 percent win rate for the Wallabies was not acceptable.

"We had to have a look and see what it is that we could do."

While Cheika was not "100% comfortable" with the changes, Castle was taken aback by his public criticism.

"Yeah, I think they surprised me," Castle said of Cheika's comments.

"At the end of the day, the CEO-coach relationships are never straightforward.

"What I can tell you is the board continued to support Michael and gave him all the support he needed going into this World Cup.

"(The shake-up) probably wasn't the ideal scenario but those changes were important to make sure we had stability in rugby (in) Australia going forward."

RA has pledged a thorough review of Australia's tournament but a slew of former players and pundits have called for an independent review, saying the governing body must be held to account for the team's equal-worst performance at a World Cup.

"They need to blow it up straight away,” former Wallabies fullback and TV analyst Greg Martin said on Fox Sports.

"Whatever the process is, the board, and there’s some duds on it, they need to go. They need to get a new CEO and a new chairman with a bit of strength."

Australian media have pilloried Cheika's coaching style and stubborn adherence to ball-in-hand rugby following the World Cup exit.

But Wallabies captain Michael Hooper defended Cheika on his arrival home on Tuesday.

"Me personally, Cheika’s been amazing for me," Hooper told reporters at Sydney airport.

"We weren’t able to execute our big moments. Our game plan was solid. We believed, we bought into the game plan 100%."

(Reporting by Ian Ransom; Editing by Stephen Coates)