Belgium would have been an overwhelming favorite to reach the quarterfinals, but the sudden retirement of Justine Henin last week leaves the match more balanced against a U.S. team that 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 Wednesday she still lacked sleep after her long trip home from Melbourne. However, she expects to be ready to play the opening singles Saturday on an indoor hard court.
"I was able to make the switch real fast," Clijsters said.
Her Australian Open cup will be prominently displayed at the 12,500-capacity Antwerp Sports Palace.
Based on ranking, No. 48 Bethanie Mattek-Sands and No. 61 Melanie Oudin of the U.S. should be no match for No. 2 Clijsters and No. 26 Yanina Wickmayer. But the U.S. record in recent years shows the Americans haven't needed the Williams sisters to advance. They reached the last two finals, losing each to Italy.
The U.S. team also includes Vania King and doubles specialist Liezel Huber.
"It's almost as a family reuniting, these Fed Cup weeks," U.S. captain Mary Joe Fernandez said.
And facing a favorite, often away from home, no longer scares them.
"It is always a challenge when you're an underdog, but it is something our team really thrives on," Fernandez said. "It brings out the best in our team."
The Belgians have already heeded the warning.
"They perform great when they feel they are part of a team," Clijsters said.
Mattek-Sands already hit her groove early this season, helping the U.S. mixed team win the Hopman Cup.
Clijsters is thriving in just about every situation these days. She made the final in Sydney before winning her first Australian Open crown, which puts her within reach of regaining the No. 1 ranking.
Wickmayer suffered through a nasty cough and cold, losing in the second round in Melbourne.
The Americans will be targeting the Wickmayer match on the opening day. After two singles on Saturday, there's reverse singles and a possible deciding doubles on Sunday.
The U.S. hasn't won the Cup since 2000, a 5-0 win over Spain.