Europe's footballing governing body acted quickly to urge that any restrictions on the goalkeeper playing would contradict the 'integrity of competitions,' describing it as a violation of their rules.
The Belgian is now likely to feature in both semi-finals for Atletico Madrid against Chelsea, and there could be a precedent the Premier League look to follow.
Loan deals have been debated on numerous occasions this season, with the most high profile opponent being Arsenal boss Arsene Wenger.
The Frenchman argued earlier this season: "I believe that if you want to continue the system we have to make them available against the teams that loaned them out - or the system is not defensible.
"This is not something against Chelsea or Man City, it’s just that the whole system has to be considered."
Wenger's side were on the wrong end of a goal from a Chelsea loanee, Romelu Lukaku, when they lost at Everton a fortnight ago.
Lukaku was ineligible to play in the two matches against Chelsea in the Premier League.
A key part of the Everton side in their charge, Arsene Wenger argues that the rules should be the same across the board.
UEFA clearly sit on the same side of the fence as the Frenchman. Surely this move means it is only a matter of time before the Premier League do too?