The 26 year-old has appeared in three international tournaments -- the World Cup, the Asian Games and the Asian Cup -- in the past 12 months and has also been busy helping Tottenham challenge in the Premier League and UEFA Champions League.

While Son has been in excellent form for the London club, he was less effective for his country in January's Asian Cup as the Taeguk Warriors were eliminated at the quarterfinal stage against eventual champions Qatar.

Son's selection kicked off another round of debate in Korea as to how the Spurs star should be best used for his country. National team coach Paulo Bento is keen to find the perfect position for Son as thoughts turn in Asia towards qualification for the 2022 World Cup.

"It's not just Son but I consider carefully how to use each player in each position to get the best results," Bento told reporters at Paju Football Center on Monday morning.

Son Heung-min will play for South Korea for their home friendlies against Bolivia and Colombia. Matthew Ashton - AMA/Getty Images

Bento has handed first call-ups to Spanish-based duo Lee Kang-in of Valencia and Girona's Paik Seung-ho. Just 18 and 21 respectively, Bento is confident they can handle international football.

"They both have plenty of talent," added the former Portugal boss. "We have watched them closely in a number of different situations and I would like to get a look at what they can do in the long-term."

French-based midfielder Kwon Chang-hoon returns to international duty after suffering an achilles injury in May 2018. After their retirements from national team duty Ki Sung-yueng of Newcastle United and Koo Ja-cheol of FC Augsburg will stay with their respective clubs in England and Germany.