(CNN) When Son Heung-Min fired home Tottenham's first ever goal at its shiny, brand new $1.3 billion stadium earlier this month it felt like the next chapter in an extraordinary story.

For Son, this season has been one of personal success and recognition from across the sport. His 21 goals for Tottenham Hotspur -- Spurs to their fans -- so far this season, more than he managed in the entire campaign last term, have taken his game to new heights.

For a player who previously revealed he was close to leaving English football back in 2016 , Son's rise with Spurs has been meteoric.

So, too, has been his popularity. Not just with his teammates and Tottenham's supporters, but also back home in South Korea and across much of Asia where his social media profile has rocketed.

Much of that is down to his outstanding performances for Tottenham in the Premier League and Champions League, where he has been one of the club's leading players, scoring twice in the second leg against Manchester City to propel his team to the Champions League semifinals for the first time in its history.

According to figures provided to CNN by Nielsen Sports, which carried out an analysis of his social media audience, Son is the most popular athlete in Asia.

The research showed that Son had the highest number of followers across social media with 1.98 million, beating Japanese soccer player Shinji Kagawa in second place.

Rabid fanbase

Both on and offline, Son's popularity continues to soar.

It's not unusual to see South Korean flags being worn to Tottenham games, while Korean supporters often wait outside Tottenham's training ground hoping to get a glimpse of the man himself.

A fan of Son Heung-min of Tottenham Hotspur with a balloon honoring the South Korea star.

"Son is one of the most popular personalities in South Korea. In other words, his popularity goes beyond the category of football, or sports," Korean football journalist Lee Sungmo told CNN.

"In the whole country, most of the people know who Son is, and they feel proud when Son is doing well in Europe."

Sungmo, who writes for football website Goal.com, has followed Son's journey at Tottenham since the player's home debut, where he scored the only goal of the game in a 1-0 win over Crystal Palace, back in September 2015.

"I have to say football is already a very popular sport in South Korea. Especially since the 2002 Korea/Japan World Cup, we had Ji-Sung Park who played for PSV and Manchester United, who was excellent in many ways. Many fans followed European football ever since that time."

A Tottenham fan poses for a photo with his Son themed posters.

Big game player

Son's winning goal in the first leg of Tottenham's Champions League quarterfinal against Manchester City showed once again his ability to show up for the big moments.

Having moved away from home as a teenager to join German club Hamburg, Son enjoyed great success in the Bundesliga after making his debut in October 2010, eventually scoring 20 goals in 78 appearances for Hamburg before joining Bayer Leverkusen in June 2013, where he helped the club secure Champions League qualification in both of his two seasons there.

His goal return of 29 in 87 games persuaded Tottenham to shell out a reported $28 million for the player in 2015.

South Korea's forward Heung Min Son celebrates after winning gold at the 2018 Asian Games.

Since then his profile has rocketed, particularly this season with his goals ensuring Tottenham remain in the top four of the Premier League and in the last eight of the Champions League.

There was the added bonus of leading the national team to a gold medal at the Asian Games in September, a victory that ensured an exemption form military service.

"I don't think football has become more popular thanks to Son but it's a fact that Son is the best and most popular sports player in South Korea at the moment," Sungmo added.

"And most importantly, Son is making a new history of South Korean football, breaking most of the records, leading Korean football into a high level."

Son has been one of Tottenham's most impressive players this season.

Marketable star

His popularity is also likely to attract the attention of sponsors and marketing companies as they look for the next big star in world football.

Simon Chadwick, professor of sport enterprise at the University of Salford, believes Son has "considerable potential" as a brand proposition given his success on the field and low-key persona off it.

South Korea's Lee Seung-woo (L) celebrates with teammate Son Heung-min (R) after scoring against Vietnam.

"In many ways, Son Heung-Min's commercial profile parallels his on-field presence," Chadwick told CNN.

"That is, low-key, if not sometimes almost anonymous. He doesn't appear in rankings of most marketable athletes or on lists of high value football player brands.

"This suggests that his focus is on playing football rather than on garnering the often lucrative revenues that most modern footballers would normally seek to earn.

"It is this devotion to football and performance that is both creating his brand whilst at the same time generating commercial opportunities for him.

"It will be a tricky decision for Son and his advisers to identify what the appropriate balance of activities for him should be. That is, assuming Son wants to position himself as an endorser, a brand and a commercial entity.

Son scored the winning goal in his side's 1-0 victory over Manchester City in the quarterfinal first leg.

"As a brand proposition, Son has considerable potential. He plays well, scores and has had some career success. Yet in many ways, he is the epitome of many East Asian young people too; he talks about the importance of respect, of being close to his family and listening to what his parents say, of putting career ahead of girlfriends and marriage, and so forth.

"In overseas markets like South Korea, such qualities are valued and provide a point of engagement with actual and prospective fans. "

Chadwick believes there is huge potential for Son to enhance is brand in South Korea, the world's 11th largest economy, where football is the second most-popular sport. He also believes his clean-cut image will resonate across the rest of East Asia.

"What happens beyond East Asia will be interesting, as in many ways is brand is the antithesis of what modern footballers look like and are -- no crazy hairstyles, no tattoos, no high-profile celebrity partners, no reports of bawdy behavior," Chadwick added.

"This may play out well among brands for which a wholesome image and clarity of messaging is needed. It's almost as though Son could be the everyday hero in a Disney movie, which perhaps says everything prospective commercial partners need to know about his brand and its positioning."