Tottenham's South Korean striker Son Heung-min began his three-week military training at a marines boot camp on Monday with the Premier League on hold over the coronavirus pandemic.
Most South Korean men are obliged to serve in the military for nearly two years, making up the bulk of Seoul's 600,000-strong forces.
An official at the Marine Corps said Son would receive a shortened version of a boot camp required for all new regular enlistees, including discipline education, combat drills and a chemical, biological, radiological and nuclear (CBRN) exercise.
Son was among the South Korean footballers who earned an exemption by winning gold at the 2018 Asian Games in Indonesia.
The 27-year-old's Premier League season ended even before the coronavirus outbreak spread to Europe when he broke his arm against Aston Villa on February 16, and Spurs said he returned to South Korea for "personal reasons".
Son reported to a marines camp on the southern island of Jeju for his three-week basic training, Yonhap news agency reported.
A photo showed Son walking past a military truck and soldiers, wearing a green sweatshirt, a black cap and a face mask.
"South Korean football star Son Heung-min enters the training facility of the 91st Battalion of the 9th Brigade of the Marine Corps," the caption read.
Son's agency had earlier urged fans to refrain from attending the venue over virus concerns.
"Son Heung-min is up for basic military training in April," his agency said on his official Facebook account this month.
"We have decided to not open to the public in active compliance with the government's measures on the Covid-19," it added.
Under the terms of his gold-winner's exemption, Son only needs to complete his basic training and perform around 500 hours of community service to satisfy his conscription obligation.
Basic training in the army is four weeks, but three weeks in the marines and navy.
A video of military training posted by the Military Manpower Administration on YouTube showed a group of soldiers undergoing CBRN training in a gas chamber. After a few minutes they are let out, tears streaming down their faces and pouring water over their heads.
"The CBRN training is usually the toughest part of the boot camp," the video says.
The Marine Corps official said Son would wrap up the three-week service period with a group march of up to 30km.
"Once you're in the military, you should be able to fire a rifle, breathe in the gas and participate in a battle, rolling and crawling around the field," the official told Reuters.
"During the march, our regular Marine Corps recruits would bring 40 kilograms of equipment but it could be much lighter for alternative trainees depending on the programme."
He said the military would conduct regular temperature and medical checks on all servicemen and required them to maintain distance during the training to prevent any coronavirus infections.
The Premier League has been suspended since mid-March because of the coronavirus and no date has yet been set for a resumption.