Emma Raducanu cut short her practice session at Wimbledon before cancelling a scheduled press conference as concerns about her fitness deepened.
The British No 1 has been at the centre of another injury scare since she was reportedly seen wearing a protective boot on Wednesday evening.
Raducanu did not train at Wimbledon on Thursday or Friday but was down for two hours of hitting on Saturday, first at the All England Club's Aorangi Park practice courts and then on Court Three with Russia's Anna Kalinskaya.
Raducanu took to the court with strapping on her right ankle and lower leg but made it through the first hour and a half without any alarms.
However, she was largely hitting from the same position and it was when she began playing points against Kalinskaya that things took a worrying turn.
Raducanu struggled on serve and was 4-0 down against the world No 20, while her body language in discussions with coach Andrew Richardson indicated she was far from content.
Midway through the next game, Raducanu abruptly called an end to the session 10 minutes before it was due to finish and hugged Kalinskaya before quickly leaving the court.
Raducanu had been due to speak at a press conference on Saturday afternoon but 20 minutes after walking off court it was announced she would be speaking on Sunday instead.
There must be serious doubt now whether the 23-year-old will even make it onto court for her scheduled first-round match against Croatian Antonia Ruzic at 1pm on Monday.
Should she have to pull out, it would be the latest setback in another stop-start season, with Raducanu having missed two-and-a-half months due to a post-viral illness during the spring.
Things appeared to have taken a positive turn when, after rehiring Richardson, with whom she won the US Open in 2021, as coach, she reached the final at Queen's Club two weeks ago.
But Raducanu has not played a match since and the story once again centres on her physical fragility.
It has been another stop-start season for the former US Open champion, who missed two-and-a-half months with a post-viral illness having initially fallen unwell in February.
She played just two matches on clay but things appeared to have turned around at Queen's Club, with Raducanu reaching just her second final since her historic run at the US Open five years ago having reunited with coach Richardson.
However, it appears the physical toll of that run in west London, which included playing two matches in a day because of rain, could now impact her chances at Wimbledon, which begins on Monday.
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