Injured Venus Williams will join her sister Serena on the Fed Cup sidelines with Vania King named to take her place on the US team that will play the quarter-finals in Antwerp against Belgium.
US captain Mary Joe Fernandez named King, Melanie Oudin, Bethanie Mattek-Sands and Liezel Huber to her team Tuesday for the Feb 5-6 indoor matches at the Sports Palace.
At number 48, Mattek-Sands is the highest-ranked player on the US squad.
Fifth-ranked Venus, a seven-time Grand Slam singles champion, was expected to be on the squad before injuring her hip last week during the Australian Open.
Fourth-ranked Serena, winner of 13 Grand Slam singles titles, has not played in a tournament since Wimbledon last July because of a foot injury.
The Belgian team is expected to include U.S. Open champion Kim Clijsters, ranked third, and seven-time major winner Justine Henin (13).
"We will have our work cut out for us," Fernandez said in a conference call after naming the team. The United States has won 17 Fed Cup titles, but have not triumphed since 2000.