Son has 2 years left this summer according to this.
https://www.transfermarkt.co.uk/heung-min-son/profil/spieler/91845
He can refuse to sign a deal if he likes, and then move on a free at 31, but I think its far from certain that he'd be making a step up at that point if he does (unless its a rich/big team with piles of cash and who is going through a mini-crisis)
https://www.transfermarkt.co.uk/heung-min-son/profil/spieler/91845
He can refuse to sign a deal if he likes, and then move on a free at 31, but I think its far from certain that he'd be making a step up at that point if he does (unless its a rich/big team with piles of cash and who is going through a mini-crisis)