The Wallabies gained a massive boost for their spring rugby sojourn when skipper George Gregan made himself available to tour.

Gregan was in doubt for the tour to the northern hemisphere after his son Max was recently diagnosed with epilepsy.

He confirmed his participation for the tour, saying while his family came first they would manage.

"It's obviously a difficult time for the family and one of the most difficult decisions I've had to make, but they'll be okay."

Gregan, however, left the door open to quit the tour should his son's condition get any worse.

"There will not be any problem if I quit the tour, if the situation gets worse I will come back."

He said the withdrawal of his backup Chris Whittaker from the travelling squad because of injury did not play a part in his decision to tour, but Whittaker's loss was a disappointment.

Earlier squad member Phil Waugh spoke of Gregan's importance to the team.

Waugh, who along with Wallabies teammate Lote Tuqiri was at Sydney's Red Cross Donor Centre to highlight the need for more blood donors, said Gregan's influence extended far beyond the football field.

"His leadership ... not just on the field, but just around camp and on tour, is hugely important to the side," Waugh said.

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