Toua Udia, 22, denies intentionally or recklessly touching the man's testicles in a coffee shop toilet in Tesco on Dalmarnock Road in Rutherglen, South Lanarkshire, on July 21.
The trial was delayed at Glasgow Sheriff Court this morning while Sheriff Martin Jones decided whether Udia, from Papua New Guinea, was competent enough to understand the proceedings.
About 800 languages and dialects are spoken in Papua New Guinea and concerns were raised that Udia's interpreter did not speak the required dialect of pidgin English.
Sheriff Jones decided that a verbatim translation was not required and the trial could proceed with reference to photographs and anatomical diagrams if required.
Udia's accuser began his evidence in the early afternoon, insisting the athlete touched his testicles while he was helping him to strap an ice pack to his leg.
"I came out of the cubicle and saw him strapping a bandage to his left calf," he told the court.
"I asked him: 'Are you okay?'. He asked me if I could help him tie the bandage.
"I went to his right side and he said: 'No, the other side'.
"I took both ends of the bandage and he said: 'Pull it tight'.
"I held it as tight as I could and he put his left hand between my legs and touched my testicle with two fingers.
"There was a bit of pressure. It wasn't a scuff and it wasn't a total grab, but it was definitely as if someone was poking.
"I said: 'Hey!' to tell him to back off. He looked at me and just smiled as though it was normal, with a wee smirk, as if everything was fine."
The accuser said he did not consent to the contact or wish it to happen, and that he left the toilet and alerted staff and the police.
Procurator Fiscal Depute Adele MacDonald said: "It might be suggested that you are not telling the truth today and that you are looking for media attention given that Mr Udia is in the Commonwealth Games."
The accuser insisted he is not looking for media attention.
Ian Moir, defending, said: "This case is one which has had a huge impact on (Udia), particularly because his career hangs in the balance.
"His family contacted me over the weekend to indicate how terribly difficult they were finding it, including the problems that a case of this type has brought to Mr Udia and his family."
He outlined the communication difficulties his client has had with the interpreter, who has been trained and approved by the Home Office but admitted that he did not speak Udia's stated dialect.
Mr Moir said: "The delegation to the Games have done their best to assist and have advised that there are 800 languages and dialects in Papua New Guinea alone, so these have been simply to do the best possible without the correct resources.
"The secretary to the High Commission of Papua New Guinea in London Nasser Tamei has also raised concerns to me about about this issue."
He added: "An experienced interpreter has submitted that that he doesn't speak this language and he has never interpreted in it before, but that he will try to explain in a language that he is not sure about. My submission is that is not good enough."
Sheriff Jones dismissed these concerns and the trial continues this afternoon.