The South Korean international came close to a move to Premiership side Blackburn last August, and was then briefly linked with Spain's Atletico Madrid earlier in the year but both deals ultimately fell through.
However, the 27-year-old now feels that a move to Europe is just around the corner.
"Timing-wise, it would be best to go this summer. If not, it might be a little more difficult," said the World Cup star.
"Both the English and Spanish leagues have some of the best players in the world, so it would be a great experience to play in either country.
"If I played at a club where first-team chances were limited, it might not be the best situation for me. It would be a bit of a dilemma.
"But if I was playing regularly for a mid-table club and doing well, hopefully I could move to one of the top teams. Those are the sort of targets you want to set yourself as a player.
"The World Cup raised my profile, no doubt. I still have a good chance of playing in Europe."
