Malaysian Ayuni won gold in the 10 metre air rifle pairs in New Delhi four years ago.
She had been set to compete in the 10m air rifle and 50m rifle prone events in Glasgow, but will now be reduced to the role of spectator after her luggage went missing en route to Glasgow and failed to be returned in time for Monday's registration.
The misfortune left team manager Musa Omar with no option than to withdraw Ayuni from competition.
"She was a gold medallist last time and now she won't even get a chance to compete. It is really painful for her. I just feel so sorry for her," Musa was quoted as saying by Malaysian media.
"We made a report when her bag did not arrive with the other luggage. We waited for three days... today [Tuesday] is the last day for us to confirm the names.
"The rules clearly state that a rifle shooter must wear a jacket.
"We tried to borrow one but it did not fit her. We tried to make a new one but she said that she would need two months to get used to it."
Musa revealed how a devastated Ayuni was keen to return home following her withdrawal, but is required to watch her team-mates from the sidelines.
"The licence for all her firearms is under her name. We cannot send her back immediately," Musa added.
"This is all so unfortunate. She's taking it badly. She is sad, we are all sad."