The doctor had an appointment, so Hong Kong's Zoe Ng On-yee was ordered to stop mid-match to have a doping test during last week's IBSF World Snooker Championships in Hyderabad, India.
The 19-year-old snooker prodigy was leading 4-1 against Australian veteran Kathy Parashis when the rude interruption came.
Why, we wonder? Surely an athlete is tested for drugs only after a competition, or pre-competition, certainly not during it.
Hong Kong coach Chen Chor-kwan threw light on the bizarre happenings in Hyderabad when he revealed there was nothing sinister behind the mid-match request other than that the doctor had an aircraft to catch.
'The doctor had to leave so the officials decided the match be interrupted and Ng told to give a urine sample,' Chen said.
'It is not the normal practice, but she was okay with the request.'
Ng said the test helped calm her nerves and that she returned to the table in a more relaxed frame of mind.
'I was actually more composed and I potted well, too,' she said.
Ng was crowned world champion after beating Parashis 5-1 in the final.
Joseph Lo Tsun-ying, secretary of the Hong Kong Billiard and Snooker Sports Control Council, laughed when asked about the out-of-the-ordinary drug test.
'The doctor was from New Delhi. He had a flight to catch and the best-of-nine-frame final was running late,' Lo said.
'The other girl had undergone the test before the match started but Zoe was a bit late turning up.'
So there was no hint of conspiracy or controversy and Hong Kong snooker has its first women's world champion, a teenager who honed her skills in a Sheung Wan snooker parlour owned by her father, learning the fine art of in-offs and long-range potting.
Snooker is one of the 22 sports in the East Asian Games, which start on Wednesday, although the opening ceremony is on Saturday. Officials are hoping the tables will be running warm and that they will produce a clutch of gold medals for Hong Kong.
Sadly, Ng will not be in the mix. She lost out in the selection process earlier this year as she was ranked third behind teammates Jacqui Ip Wan-in and Yu Ching-ching. She had also informed officials she would not be able to attend squad practice.
So with only two berths available, Ng will have to settle for being a spectator when the cue sports begin on Thursday.
Ip and Yu will be taking part in the women's six-red snooker singles at the International Trade and Exhibition Centre in Kowloon Bay. There is another women's event - nine-ball pool singles - but Hong Kong failed to qualify.
In July, snooker joined athletics and karate as sports on the elite roster at the Hong Kong Sports Institute. Previously, Hong Kong's top professional, Marco Fu Ka-chun, received individual backing from the institute, but now the sport as a whole gets financial support and other backing.
Apart from the East Asian Games, the sport's other major target is next year's Asian Games in Guangzhou. Hong Kong have won several medals, including gold, in snooker at previous Asian Games. As such, it is seen as a good source of more honours in the future.
Ng's triumph will add more fuel to those convictions, and Lo said that the win would further boost snooker's credentials at the institute, which supports 11 sports.
The bespectacled Ng is a talent worth keeping an eye on. For two years running, Ng won the Hong Kong Under-21 snooker championship, participating in the boys' section and giving them a good hiding. The best feature of her game, observers say, is her long-range potting.
Lo said it was because of her father's influence that Ng fell in love with the game. Now there is talk that perhaps she could one day follow in the footsteps of Fu and turn professional.
Like Fu, she would then have to go to England, where the professional game in centred. But not all of the leading women's professionals follow that route, because the more lucrative pool circuit in the United States is enticing many to play there.
'Even the top girls like Alison Fisher [a former women's world champion from England who is nicknamed the Duchess of Doom] have gone to play on the pool circuit in the US, which offers more money and has more exposure on television,' Lo said.
'We don't know what Ng will do in the future, whether she will want to play pool or stay with snooker. It is too early to say.'
Ng is part of the youth squad at the institute, which has about 10 snooker players in the frame. Whatever decision she takes, one thing is certain: Hong Kong will be able to depend on her skills for future medals.
'At next year's Asian Games, women's snooker will figure for the first time with both singles and team events,' Lo said.
'We hope Ng will be in the picture in a big way. She is, after all, a world champion, the first Hong Kong woman to have won that honour.'
Unfortunately, her timing was lousy. If Ng had been crowned before the selection process had taken place, we could have witnessed her long-range potting at the East Asian Games.
Instead, Hong Kong will have to rely mainly on Fu and the men to bring glory for the home team.