"Son Heung-min's position is not determined yet, so I can't say much about his partner as well," Shin said before training at FAI National Training Centre in Dublin. "I'm going to start my players based on their fitness and performance, not just for testing purposes."

At the 2018 World Cup, South Korea are in Group F with Germany, Mexico and Sweden. Shin said their friendly against Northern Ireland is to prepare for Sweden.

"Northern Ireland have a similar style of football to Sweden, and they are a counterattacking side," he said. "I'm not sure Northern Ireland will display their traditional style against us, but we'll try to find what we should prepare for when we meet Sweden."

With the 2018 World Cup less than three months away, Shin said what he emphasizes to the players at this moment is sacrifice and unity.

"All teams at the World Cup are stronger than us," he said. "I emphasize that if all 23 players make an extra effort, we don't have to be afraid of any team in the world. With a do-or-die mindset on the pitch, I told my players that we're not going to just fall down easily even if our opponents are the world No. 1 Germans." (Yonhap)