An emotional Australian captain Michael Clarke has paid tribute to "one of the world's greatest blokes", teammate Phillip Hughes who died this week after an on-field accident at the SCG.

Hughes, 25, was struck by a rogue bouncer that hit him in the head while playing a Sheffield Shield match at the Sydney Cricket Ground on Tuesday. He died in hospital on Thursday afternoon.

Clarke announced today that Hughes' Australian One Day shirt number 64 will be permanently retired.

Clearly emotional and stopping to wipe away tears several times he said the statement was on behalf of the Australian cricket team and support staff.

"We are going to miss that cheeky grin, that twinkle in his eye... he epitomised what the baggy green was all about," he said.

"Words cannot express the loss we all feel as a team right now.

"To Greg, Virginia, Jason and Megan we share in the deep pain that you’re feeling.

"Apart from when he was home on the farm with his beloved cattle Hughesy was at his happiest playing cricket for his country with his mates."

Clarke then took a long pause before going on.

"Things were always put into perspective when Hughesy said: 'Where else would you rather be boys, than playing cricket for your country?'," he said.

"The world lost one of its great blokes this week and we are all poorer for it - we love you and we always will."

Clarke's comments join a host of international tributes for the young left-handed batsman.

People around the world have put their cricket bats out in tribute to the late cricketer as part of the #putoutyourbats campaign and this morning, junior clubs observed somber moments of silence across Australia.

Cricketers in Sri Lanka, England, India and Pakistan observed moments of silence.