Ashley Harkleroad led the United States into the Fed Cup World Group semi-finals by winning her two singles matches against Germany but could be dropped for the next round.

The U.S. meet champions Russia in the last four, almost certainly on a slow clay surface in Moscow, and accept they have to field their strongest team to have any chance of progressing.

If available, their best singles players would come from the Williams sisters, Serena and Venus, and former world number one Lindsay Davenport.

"It all depends who we get to field," Davenport said after winning her last two rubbers on Monday in the first-round tie against Germany.

"If we can field our strongest team, we have a great shot (against Russia). If not, it's going to be tricky because it's going to be, I'm sure, on a slow red clay court which is obviously not the Americans' best surface.

"We are fired up. We're going to try and talk either Venus or Serena into coming."

Neither of the Williams sisters was available for the La Jolla tie, although Venus did consider playing in it.

"Venus had me wait probably till a week up until (the team was announced)," U.S. Fed Cup captain Zina Garrison said. "She was going back and forth. She basically said she played five weeks straight and couldn't do it. Look for her in April."

The seventeen-time champions are bidding for their first Fed Cup title since 2000 and face Russia in on April 26-27.

The Americans lost to the Russians 3-2 in last year's final on a hardcourt surface in Vermont.

"I'm tired of Russia," Garrison said. "I want the ones (players) who are here right now just to enjoy the fact that we have the opportunity to go to Russia."

Harkleroad, who sealed victory for the U.S. by beating German teenager Sabine Lisicki 6-4 7-5, said she would not be disappointed if overlooked.

"It just means that I would be able to continue to play tournaments and work on my own ranking, continue to play and continue to move up," added the 22-year-old, who crushed Tatjana Malek 6-1 6-3 in Saturday's opening singles.

"So I wouldn't be disappointed. They (Russia) are a tough team. But I definitely would be all for it if they asked me to go to Moscow, for sure."

Reuters