Shin said taking 18 players to the tournament is different from taking 23 players to other major events like the FIFA World Cup, for the smaller squad leaves coaches with fewer roster options.

"We selected players who can play in multiple positions because we need them to replace others when there is a problem," Shin said at a press conference in Seoul. "Here (at the Olympic team), a player shouldn't just do well in one position."

Usually, teams take four or five alternates who can replace injured players at the Olympics. But this time, Shin decided not to name alternates because of the long travel and consideration for pro clubs.

This also forces Shin to maximize the use of his 18 players at the Rio Games. And the players, except the two goalkeepers, should carry out at least two roles on the pitch.

Fortunately on Shin's 18-man squad, most players are known for their versatility, including the three wild card players. Tottenham Hotspur forward Son Heung-min, who turns 24 in July, can play in any attacking position, although Shin said he will use him as a left wing forward. FC Porto striker Suk Hyun-jun who turns 25 on Wednesday, is known for his powerful plays up front, but he has been playing on the flanks, right or left, in certain situations.

Jang Hyun-soo, 24, will be the utility man on the back. The Guangzhou R&F defender mainly features as a center back, but he can also play as a side back or a defensive midfielder.

"We will use him depending on the match situations, but we are going to make him focus on only one or two positions," the coach said.

Shin has shown concern for his two side backs, Sim Sang-min of FC Seoul and Lee Seul-chan of Jeonnam Dragons, over their lack of playing time with their clubs. If he wants to reinforce the defense against wingers, Shin is likely to put Jang on the flanks.

Other young players are also known for playing in multiple positions. Suwon Samsung Bluewings midfielder Kwon Chang-hoon has been covering center and flanks, while Ryu Seung-woo, who played for the second-tier German club Arminia Bielefeld last season, can also handle almost any attacking position.

Despite having versatile players, Shin, however, said his team at the Olympics will not show various tactics like they did at the AFC U-23 Championship in Qatar, which also served as the Asian qualifying tournament for the Rio Games. In Brazil, Shin's side have been paired with Fiji, Germany and Mexico. 

"In Rio, I think we need to stick to one or two formations," he said. "All of these players are needed for our tactics to work well. I will not tell this player is selected for this tactic because that will have a bad influence on our team's atmosphere."

With the squad finalized, Shin's next step will be gathering players for training, but there is a bump in the road on the way to Rio. South Korea, in their eighth consecutive Olympics, will depart for Sao Paulo on July 18 to set up camp there, and will face Iraq on July 25 behind closed doors and then Sweden five days later in final tune-up matches.

However, Shin said there will no training in Korea because he finds inefficiency in the schedule. Shin can call up the players from July 4, a month before South Korea's first match against Fiji, but at the same time, the players can't avoid their club duties. Because those who play overseas will feel tired of traveling frequently between the club and the Olympic team, the coach decided to scrap the domestic training.

"The K League office and the Korea Football Association changed their competition schedule for us, but still it's impossible to gather a majority of players," he said. "Personally, I feel sad about not having a training session in South Korea, but I can't be greedy."

Shin, however, vowed that his players will be fit once they start training at their base camp in Sao Paulo and play friendly matches. The coach added he will make the young players' mindset strong.

"If we don't collect good results in friendly matches, our players might see negative news on the internet and that will affect their mentality," he said.

At the Rio Games, South Korea will first face Fiji at Fonte Nova Arena in Salvador on Aug. 4 before taking on Germany three days later at the same venue. South Korea will then travel to Mane Garrincha Stadium in Brasilia for the final group match against defending champions Mexico on Aug. 10.

Shin said his team will not show all of their skills in the first match against Fiji. He announced that Son Heung-min will not play against Fiji because he will join the team five days before the match after completing his club's preseason friendly matches against Juventus and Atletico Madrid in Australia.

"We will try to hide things in a match against Fiji, but will put all of our efforts against Germany," he said. "If we beat Fiji and manage to get a win or a draw against Germany, then we can focus on Mexico. If we can't accomplish our goal from the start, then I consider South Korea are in the 'group of death.'" (Yonhap)