Australia captain John Fitzgerald says Hewitt and Philippoussis are no guarantee that Australia will breeze through the Davis Cup match with an injury-racked British team.
The Swiss ace will play David Nalbandian in the quarter-finals of the Australian Open.
The move is designed to favour 2002 Wimbledon champion Lleyton Hewitt and this year's runner-up Mark Philippoussis.
Tennis coach Gavin Hopper was found guilty of charges relating to a teenage girl who attended a school where he taught.
The Australian was the only non-British player given an invite into the main men's draw.
Agassi remains top of the 12-month rankings with 4,090 points followed by Ferrero and Federer.
The big-serving Aussie beat Sebastien Grosjean in the first men's semi-final at Wimbledon.
The world number one repeated his Australian Open final victory over Marat Safin with a 7-6, 7-6 win to reach the second round of the Dubai Open.
Morocco's Hicham Arazi upset the local favourite 6-2 6-2 6-4 in the fourth round of the Aus Open.
The Aussie ace feels his rapid slide down the world rankings could give Australia the advantage in the Davis Cup final against Spain.
Mark Philippoussis will lead Australia in the Davis Cup final against Spain to be held in Melbourne.
The third seed Thai was two points away from defeat against close friend Lee Hyung-taik at the Japan Open.
The top seed overcame a bad start to beat Kenneth Carlsen in the Mercedes-Benz Cup.
Federer has become the first Swiss man to win a Grand Slam singles title.
The world No. 1 needed just 85 minutes to defeat Mark Philippoussis in the final.
The Argentine joined third seed Rainer Schuettler, fifth seed Mark Philippoussis and sixth seed Tim Henman as a first round loser.
Sweden won both the concluding reverse singles to emerge 4-1 winners in the first round of the Davis Cup.
Local favourites Lleyton Hewitt and Mark Philippoussis were brought to their knees in the fourth round of the Australian Open.\n\n
The Australian wasted five match points and a chance to play in the season-ending Masters Cup when he was beaten 6-7, 7-6, 7-6 by Gustavo Kuerten.
Spain's Feliciano Lopez sent the Australian ninth seed spinning out of the Madrid Masters on a night of surprises.
In the semis, Hewitt beat Nicolas Kiefer while Ferreira dumped Mark Philippoussis.
Less than 24 hours after Federer won a men's singles Grand Slam title, the enormity of his achievement was slowly sinking in.