Australian captain John Fitzgerald defended Mark Philippoussis's honour after the former grand slam finalist opted out of this weekend's Davis Cup loss to Argentina - only to play Team Tennis in American instead.

The mercurial Victorian's commitment to the Davis Cup cause has been a constant issue throughout his fluctuating career and the subject rose again after a bare-bones Australian team suffered a 4-1 home loss to the South Americans in Sydney over the weekend.

But Fitzgerald deemed Philippoussis's unavailability as he recovered from an ankle injury suffered at Wimbledon last month to be fair enough.

"It was a mutual decision and he felt his body wasn't ready to stand the rigours of what this takes," he said.

"You've got to be in mighty good shape to go five sets with these guys. I think it was the right decision that we mutually made that his body wasn't ready."

Philippoussis's absence left Lleyton Hewitt and Wayne Arthurs to carry the burden of playing both singles and doubles against Argentina.

Hewitt, though, also seemed to accept that Philippoussis wasn't ready for the intense demands of Davis Cup after tumbling to 207th in the world rankings.

"I know that Fitzy was obviously desperate to have Mark here as well purely because he's such a dangerous player," Hewitt said.

"When Fitzy had spoken to him a few times, he was coming back ... he had to have MRIs on his ankle after Wimbledon.

"I never spoke to Mark personally but maybe Fitzy and Mark decided that he wasn't fit enough to play five sets of tennis and that could have been the reason.

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