It’s probably worth listening to the Portuguese press on Hadi Sacko to Leeds United. Over a week ago, when Sacko had pretty much disappeared off the face of transfer earth, it was reported in Portugal that Leeds United had agreed to activate their purchase clause.
The Portuguese newspaper reports that, as part of the Sacko deal, Leeds United are committed to paying Sporting 20% of future transfer profit.
So, for example, if Leeds one 
day manage to get €20m for the player, they’ll owe Sporting 20% of €18m, so €3.6m.
Sporting are increasingly keen to get such clauses in contracts and it was likely a condition of the Leeds United redemption right, turning the loan into a permanent deal.
