It was then about Brazilian star Hulk, who signed with Shanghai SIBG for more than $58 million.
Over the next three years, he was joined by other big names for higher prices, such as Oscar, Carlos Tevez, Ezequiel Lavezzi, Alex Teixeira and Jackson Martinez.
The "boom" in the signing of football stars came at a time when Chinese President Xi Jinping wanted to turn the country into a "football country".
As Chinese Super League clubs spent large sums of money to sign players and improve their form, senior coaches were warning of what they saw as a "real danger".
Antonio Conte, who was coaching Chelsea at the time, said: "The Chinese market is a danger to all teams in the world, not just Chelsea."
Veteran Arsene Wenger said his Arsenal counterpart: "Beijing is looking to have the financial strength to move the entire Europa League to China."
In 2019, the Chinese league became so valuable that Gareth Bale, who was once the most expensive player in the world, was a candidate to move to Jiangsu Suning on a 3-year contract.
But that didn't last long, as the movement became in the opposite direction, with the bubble bursting and the players leaving, and a team like Jiangsu Suning auctioned off its bus due to the difficult financial situation.
How did the Chinese league collapse?
According to the BBC, things deteriorated when, in December 2020, the Chinese Football Association announced a salary cap for players.
Before that, a "luxury tax" was imposed, which made large money transfers prohibitively expensive, and pastoralists were forbidden to name teams.
At the time, the Chinese Football Association said it hoped the moves would "reduce football money", while officials accused clubs of "burning money" and paying "exaggerated salaries" to foreign players.
These steps have contributed to reducing the salaries of foreign players and accumulating debt.
Then came the coronavirus pandemic, due to which the Chinese federation decided to hold all matches behind closed doors for more than two years, which led to a decrease in broadcast and sponsorship revenues.
In the aftermath, many clubs were dissolved due to financial crises, and only a few foreign players remained in China.