Wimbledon champion Elena Rybakina has withdrawn from the Eastbourne International, sparking concerns over her fitness for this year's Wimbledon.
Rybakina, 24, also reached the final of the Australian Open in January.
However, she had to withdraw before her third-round match at the French Open last month because of a viral illness.
She had been due to face Spain's Sara Sorribes Tormo at Roland Garros but had to pull out of the tournament.
Rybakina lost to Donna Vekic in the last 16 in Berlin last week and said she was still not 100% physically, as a result of that illness.
Ranked third in the world, Rybakina had been the top seed for the tournament at Eastbourne and has been replaced by Croatian lucky loser Petra Martic, who will face British number one Katie Boulter in the opening round.
There are three Britons in the women's singles with Jodie Burrage and Harriet Dart playing American Lauren Davis and China's Zhang Shuai respectively.