Wimbledon champion Elena Rybakina has withdrawn from this week's Eastbourne International.
Moscow-born Rybakina, who represents Kazakhstan, was due to face British number one Katie Boulter in the opening round.
Ranked third in the world, Rybakina had been the top seed for the tournament at Eastbourne, a precursor to next month's Wimbledon Grand Slam event.
Rybakina has been replaced by Croatian lucky loser Petra Martic, but there is now a huge question mark over the fitness of the 2022 Wimbledon winner.
The 17/4 second favourite for the SW19 tournament won her first Grand Slam title last year, with this year's tournament beginning on 3 July.
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.
