Real Sociedad will receive a sale percentage if Newcastle United sell Alexander Isak this summer.
The Magpies paid a club record €70m to sign Isak from La Real in August 2022 and the Swedish international has become a fans favourite on Tyneside.
21 Premier League goals in 2023/24 was the third highest in the English top flight as Newcastle ended the campaign in seventh place.
However, due to pressures over financial fair play rules, Newcastle could be forced to sell players in the coming weeks, with Isak linked to Chelsea.
As per reports from the Daily Mail, Chelsea are reluctant to break their own club transfer record, but Newcastle will demand around €136m.
That would mean a windfall of €6.6m for La Real, due to a 10% capital gains clause inserted in their agreement with Newcastle.
The small print of the clause focuses on the gap between what Newcastle initially paid for Isak and how much they could potentially sell him on for.
