The once-precocious talent known as the "Scud" because of his lightning-fast service, knows he is facing a watershed in his flagging career.

Now 28, the former Wimbledon and US Open runner-up has been in training with American tennis great John McEnroe in New York in an effort to revitalise his playing fortunes.

In Perth to represent Australia in the Hopman Cup mixed teams tennis tournament which starts Saturday, Philippoussis said he still cherished hopes of winning Wimbledon, although he had not set specific goals.

Instead he said he was aware some people believed the Hopman Cup was a make or break event for him.

"I know there's people saying 'If he doesn't do well here, this is his chance to prove it, if not then it's over for him'," he said.

"I don't agree with that, I think that's silly.

"I've worked on my fitness, you can't expect someone after training hard for two months to all of a sudden turn it on and have a great summer.

"It's not going to happen and if it does, bonus, great.

"But I'm here to start the year off strong, fresh, positive and see how I go, see how my legs come up in a best-of-five sets.

"I'm not here to put pressure on myself and say I want to get this far and this far and if it doesn't happen, 'Oh God, dud Scud' and whatever."

Ranked ninth in the world in January, Philippoussis made the fourth round of the 2004 Australian Open before sinking to lose 11 first-round matches for the year.

He was beaten in both his singles matches while representing Australia in the first-round of the Davis Cup against Sweden then also bowed out in the opening rounds of the French and US Opens.

He repeated the effort at Masters Series events in Indian Wells, Rome and Hamburg before recovering briefly to lose in the fourth-round of Wimbledon against Briton Tim Henman in June.

Since then, the injury-prone Philippoussis hasn't won a match, finishing the year with first round losses in five straight tournaments.

His horrific season was also complicated by a highly-publicised break-up with Australian pop star Delta Goodrem and rumours of a relationship with American heiress Paris Hilton.

But a noticeably relaxed Philippoussis joked about the year behind him.

"I think I can improve a little bit," he said. "There's a lot of pressure this year, I've got a lot of points to defend, so I'm quite nervous.

"No, I'm being sarcastic. I've got no points. Can it get any worse? No.

"I'm very relaxed, I've been training hard, it's all behind me, I'm looking forward to a great new year and there's no better place for me to start it off then here at the Hopman Cup."

Philippoussis, who will team with Alicia Molik to represent Australia in the event, opens his campaign against the Slovak Republic's Dominik Hrbaty on Monday.