Seven-times Grand Slam champion Serena Williams, who has an ankle injury, will be replaced by her sister Venus in the American team for this weekend's Fed Cup tie against Belgium in Delray Beach.
"It was my decision," U.S. captain Zina Garrison told reporters on Friday. "Serena was willing to play. She wanted to go, but after watching her practice this week, I felt she needed a few more days. Fortunately, we have the luxury of having so many great players to step up."
In the first match, U.S. number one Lindsay Davenport plays world number 392 Evelyne Van Hyfte, who is making her Fed Cup debut.
Four-times Grand Slam champion Venus will meet 34-year-old Els Callens in the second match.
Venus will play Van Hyfte on Sunday followed by Davenport against Callens before Davenport and Corina Morariu meet Callens and Leslie Butkiewicz in the doubles.
"I should be a decent fill-in player," Venus said.
Serena twisted her ankle two weeks ago at a tournament in Amelia Island and was forced to pull out.
"Zina made the best decision for me and the team. I have full faith in her and what she thinks," Serena said.
Even without Serena, the U.S. are heavy favourites to win the quarterfinal as Belgium are without their top two players, Kim Clijsters and Justine Henin-Hardenne, who both recently came back from injuries.
"You only need to look at the rankings," Belgium captain Carl Maes said. " It doesn't take a lot of calculation. You've got four number one players, if you take Corina as the No. 1 doubles player, and on the bench I think Zina was the No. 1 junior player."
Maes had hoped to play former junior number one Kirsten Flipkens in the singles but she has only just returned from a back injury.
"The whole preparation and emphasis has been on having a very good training week, because we know that the results will be very difficult to achieve," Maes said.
The United States have won Fed Cup a record 17 times, though not since 2000.