Son is regarded as the biggest sporting star in his homeland South Korea and the rest of the Far East.
He will become the second Asian footballer to feature in a Champions League final after Park Ji-sung played for Manchester United in their 3-1 defeat to Barcelona in 2011.
Son’s army of fans will have to wake up at 4am on Sunday to watch him in Madrid.
He said: “Everyone is going to watch the game so I’m really, really excited to play.
“South Korean people are very happy and excited. I’m playing in the Champions League final! They realise this and it’s really special.
“It’s a late kick-off time, or rather an early time in the morning back at home.