MOSCOW -- Billie Jean King urges caution.

The U.S. captain doesn't want her Fed Cup team featuring 47-year-old Martina Navratilova to get too confident for its semifinal against Belgium, which is without the world's top two players.

"Of course, we're considered favorites now,'' King said after Tuesday's draw. "But one thing you never want to do is underestimate your opponent.''

Play in the best-of-five series begins Wednesday, with Russia facing France in the other semifinal.

Justine Henin-Hardenne and Kim Clijsters, who led Belgium to its first Fed Cup title in 2001, pulled out of the tournament, citing fatigue.

The United States is also without its top players. The Williams sisters were sidelined by injuries and Lindsay Davenport is recovering from foot surgery. But the Americans have plenty in reserve.

"Not many countries have the depth we have,'' said King, adding it was easy to choose the team. "I go down the rankings and ask players if they want to play or can play.''

In Wednesday's singles, Lisa Raymond will play Belgium's Els Callens and Meghann Shaughnessy will face Belgium's Kirsten Flipkens.

"We will try to do the best result we can do,'' Belgium captain Ivo Van Aken said.

Navratilova, who has never lost a Fed Cup match, will pair with Raymond for Thursday's doubles against Elke Clijsters and Caroline Maes. Navratilova hopes to play with Raymond at the Athens Olympics.

Navratilova's undefeated singles and doubles Fed Cup record (37-0) is unmatched in Fed Cup history. She is back in the competition for the first time since 1995 and is the oldest player to compete in the 40-year history of Fed Cup.

"I consider her the greatest singles, doubles and mixed player that ever lived,'' King said. "So its a real privilege to have her on the team.''

After capturing consecutive Fed Cup titles in 1999 and 2001, the United States pulled out of the finals in 2001 following the Sept. 11 attacks and lost to Austria in the second round last year.

On the way to the semifinals this season, the United States has not dropped a match in beating the Czech Republic and Italy.

Russia is also a big favorite. Anastasia Myskina and Elena Dementieva are No. 7 and No. 8 in the WTA rankings, and Nadia Petrova and Vera Zvonareva are Nos. 12 and 13. France has only one player of the top 20 -- No. 4 Amelie Mauresmo. Mary Pierce is No. 33.

Russian captain Shamil Tarpischev caused a stir when he named Zvonareva to play Mauresmo in the first singles. Tarpischev said Zvonareva is in good shape and fresher than Myskina and Dementieva.

Myskina will take on Pierce in the second singles. In doubles, Dementieva and Petrova will face Pierce and Emilie Loit and Pierce.

France defeated the Netherlands in 1997 for its only Fed Cup title. Russia has made four finals but failed to win the title.

Russia's men beat France for the Davis Cup last season.