SYDNEY, September 3, 2008 (AFP) - Australia face a tough challenge as they try to win their way back into the Davis Cup World Group later this month against Chile with a team of virtual unknowns.

Australian Davis Cup captain John Fitzgerald on Wednesday named a six-man squad for the September 19-21 clash in Santiago -- but missing was former world number one Lleyton Hewitt, who recently underwent season-ending hip surgery.

In his absence, world number 87 Chris Guccione will be leading a weak Australian Davis Cup team on clay against a Chilean team led by Olympic silver medallist and 11th-ranked Fernando Gonzalez.

Guccione will be joined in the singles by journeyman Peter Luczak, who has not played since a first round French Open loss in May and is ranked 171 in the world.

The others in the squad are rookies Carsten Ball, 21, Brydan Klein, 19, Sam Groth, 20, and promising 15-year-old Bernard Tomic. Ball has the highest world ranking amongst them at 188th.

Doubles specialist Paul Hanley is also unavailable.

Fitzgerald conceded Australia faces a tough task.

'It's a difficult assignment,' he said.

'You'd be silly to say otherwise, but I'm actually genuinely excited because we've got new kids who are an incredibly enthusiastic group who want to go down there and improve themselves and give it a go.

'If Gonzalez is at his best, it's a difficult assignment and if (Nicolas) Massu is at his best, it's difficult.'

Fitzgerald said he was looking forward to seeing which players in his squad rise to the challenge.

Australia have won the Davis Cup 28 times, but have also been beaten 5-0 in their last two ties in South America.