"Fitzy (Fitzgerald) spoke to Mark a couple of times last week," team coach Wally Masur said at the squad announcement here on Tuesday.
"He wants to be part of the Davis Cup but form and fitness are a concern and he just needs tennis.
"We will welcome him back into the team with open arms but at the moment it's a case of him working on his fitness and improving his ranking." In his place Fitzgerald has called on sporting all-rounder Scott Draper, who is currently juggling his time between professional golf and tennis. Draper will vie with Wayne Arthurs for the second singles' spot behind world No 2 Lleyton Hewitt.
The fourth member of the Australian squad is doubles specialist Todd Woodbridge.
Philippoussis' omission was on the cards after a disastrous run of first round losses last year amid injury and personal problems.