The reason why Son Heung-min could not move to a big club from Tottenham

‌Former Tottenham Chairman Daniel Levy personally took charge of the transfer and contract management of Harry Kane and Son Heung-min, who were the core pillars of the team, providing them with 'special management.'
According to media interviews and analyses from former Tottenham insiders and scouting experts,
Chairman Levy has designated Son Heung-min—who brings immense commercial value and performance to the club—as a Not For Sale (NFS) player and a core asset, managing him specially for several years.
The specific behind-the-scenes transfer stories and management methods related to this are as follows.
Differentiated transfer management for Harry Kane and Son Heung-min
• Harry Kane's transfer method: Kane previously entered into a 'Gentleman's Agreement' with Chairman Levy, stating he would let him go if a proper offer arrived, but the negotiation process involved extreme friction.
Ultimately, even when he transferred to Bayern Munich in 2023 with one year left on his contract,
Levy was reportedly angered by the circumstances of the behind-the-scenes negotiations and imposed harsh,
stringent conditions to squeeze out every last bit of the transfer fee.