Tottenham Hotspur face uncertainty over the future of Son Heung-Min and when he will have to return to South Korea to complete mandatory military service.
Son has started the season superbly for Spurs and scored his fifth goal in five games to secure a Champions League Group E victory over CSKA Moscow on Tuesday. But the failure of South Korea's football team to win a medal at the Rio Olympics has increased the chances of 24-year-old Son eventually having to complete military service.
South Korean men are required to complete at least 21 months of military service before they turn 28, meaning Son can play abroad until July 2019, although there have been examples of delays and exemptions being granted.
Conscription laws stipulate that athletes and sportsmen who win medals in the Olympic Games or gold medals in the Asian Games are handed exemptions but are still required to do four weeks of basic training.
Son, however, was part of the South Korean team who suffered a quarter-final defeat to Honduras at Rio 2016 and missed out on a medal. That means the last chance for Son to earn a guaranteed exemption is to help South Korea win the 2018 Asian Games.
Should Son be called upon to fulfil his military service, it is highly unlikely he would be a 'soldier' with most professional footballers instead playing for the military team.
Such is the sensitivity of the issue in South Korea that Son will not answer questions about military service and it is hard to get information from his home country, where the laws regarding conscription constantly change.
While he would not relate the subject to military service, Son admitted that it was a huge blow not to win a medal at the Olympics with South Korea.
"It is true that after the Olympics I was very upset," he said. "I was really down because my heart was already in it for six months beforehand."
Tottenham considered selling Son after he told the club he wanted to leave this summer, but a meeting with manager Mauricio Pochettino convinced him to stay and the decision has paid off for both parties.