Son Heung-min needs to overcome his status as a marked man after an impressive season for Tottenham Hotspur if he is to establish himself among the game's elite at the World Cup in Russia, says South Korea coach Shin Tae-yong.
Son has emerged as a leading light of Asian soccer since moving to Tottenham from Bayer Leverkusen in 2015, becoming an integral part of Mauricio Pochettino's exciting and dynamic team over the last three seasons.
The 25-year-old scored 12 times in 27 starts for Spurs in the past season as the north London club finished third in the Premier League, however Son has yet to make a similar impact for his country.
And Shin believes the former Hamburg SV winger has become a victim of his own success.
"He's done well with Tottenham and he's one our best attacking options," Shin told Reuters.
"He enhances our team totally with his attacking ability.
"Honestly speaking, when he plays for Tottenham, Son Heung-min has great attacking partners like Harry Kane and Dele Alli and there's a synergy between them when they play.
"In our team, Son's partners are maybe at a little bit of a lower level and that makes it a little bit harder for him to show his ability when he plays for the national team."
Son is the main attraction of a Korean side that will travel to the World Cup hoping to secure a place in the knockout phase of the competition for only the third time in the country's history.
The Koreans have appeared at every World Cup since 1986 and reached the semi-finals on home soil in 2002, the first time the country had progressed beyond the group phase.
They qualified for the last 16 in 2010, losing against Uruguay to a late Luis Suarez goal, before being eliminated in the group phase in Brazil four years ago. Sights are being set once more on securing a place in the second round in Russia.
Drawn to play Sweden, Mexico and defending champions Germany, the task facing Shin and his team appears daunting.
For the former Seongnam Ilhwa coach, who steered the club to the Asian Champions League title in 2010 and will be making his World Cup debut on the sidelines, Son needs to step up to the challenge facing him in Eastern Europe.
"Son still plays well for the national team, but when he plays for Tottenham there are many good players and opposing defenses are not only focusing on him," he said.
"But when he plays for the national team, the opposition focuses on defending against Son Heung-min. Sometimes he has struggled to overcome that but now I think he's doing well.
"But to become a big player, he has to overcome that barrier."