Agnieszka Radwanska pulled out of her pre-women's singles final press conference at Wimbledon today due to illness.
The 23-year-old Polish player cut short post-match interviews yesterday after beating Angelique Kerber in the semi-finals.
She remained unwell, and a spokesman for the women's tour, the WTA, said: "She has pulled out of the doubles due to a respiratory illness and is struggling to speak today."
Radwanska withdrew on Wednesday from the women's doubles in which she was competing with sister Urszula.
Asked whether Radwanska's illness might prevent her playing in tomorrow's final against Serena Williams, the WTA spokesman declined to say.
The spokesman said it was hoped that she would be well enough to give one interview later in the day.
Radwanska's tennis was unaffected yesterday, as she posted a fine victory against German eighth seed Kerber on Centre Court.
She became the first Pole for 75 years to reach a Wimbledon singles final by beating Kerber 6-3 6-4.
The last player from her country to do so was Jadwiga Jedrzejowska in 1937, who lost to Britain's Dorothy Round.
It is customary at Wimbledon for the winner of the first women's semi-final to speak on the following day.
A tournament official announced that would not happen today, and advised more information could be gained at the WTA desk where the cause was explained.
Anything less than being at full fitness would leave Radwanska particularly vulnerable going into the final against four-time champion Williams, who was at her destructive best as she beat Victoria Azarenka yesterday.
Radwanska, who is through to a grand slam final for the first time, would become the new world number one if she wins the title.
There has never been a walkover in a women's singles final at Wimbledon, although there was one in the men's event in 1931 when Frank Shields was injured and could not play Sidney Wood.