World number seven Petra Kvitova will miss the opening day's action of her Czech team's Fed Cup final against the United States in Prague due to sickness.
Barbora Strycova of the Czech Republic will take on Sofia Kenin in the opening match, followed by Katerina Siniakova against American Alison Riske in the second rubber of the opening day on Saturday, according to the draw made on Friday.
Twice Wimbledon champion Kvitova, whose training has been limited this week due to a high temperature, could still play on Sunday.
The Czech team was heavily favoured going into the final with the defending champions U.S. fielding a squad without Serena and Venus Williams, Sloane Stephens and Madison Keys.
Yet Czech world number eight Karolina Pliskova has already pulled out with a calf injury and it is now uncertain whether Kvitova will be appear for a Czech team looking to capture its sixth Fed Cup title since 2011.
"After announcing the (original) nominations we felt that we were big favourites, but now it is far more even. It will be an interesting match," Czech captain Petr Pala said after training, according to the CTK news agency.
The final this year features the two most successful teams in the tournament's history, with the U.S. lifting the trophy 18 times. The Czech squad has won 10 times, including five times as Czechoslovakia.
The U.S. have dominated the Czechs in Fed Cup play and hold a 10-2 record against their final opponents. The nations have met twice in the final -- with Czechoslovakia winning in 1985 and the U.S. winning in 1986.
The U.S. have three players -- Danielle Collins, Kenin and Nicole Melichar -- making their Fed Cup debut.
