Belgium would have been an overwhelming favourites to reach the quarterfinals, but the sudden retirement of Justine Henin last week leaves the match more evenly balanced against a U.S. team which has reached the last two finals without the injured Williams sisters.
Clijsters, who beat Li Na for her fourth Grand Slam title last weekend, said on Wednesday she still lacked sleep after her long trip home from Melbourne, but should be fully fit to play the opening singles on Saturday.
The Australian Open cup will be prominently displayed at the 12,500-capacity Antwerp Sports Palace.
The U.S. team features Melanie Oudin and Bethanie Mattek-Sands.