On-loan Belgian goalkeeper Thibaut Courtois can face parent club Chelsea in the Champions League semi-finals, UEFA has said.
It was reported that Chelsea would demand a significant fee from the Spanish side if they were drawn together to allow the 21-year-old to play but the European football body said it expects Courtois to face the London side.
"Both the UEFA Champions League and the UEFA disciplinary regulations contain clear provisions which strictly forbid any club to exert, or attempt to exert, any influence whatsoever over the players that another club may (or may not) field in a match," a statement read.
"It follows that any provision in a private contract between clubs which might function in such a way as to influence who a club fields in a match is null, void and unenforceable so far as UEFA is concerned.
"Furthermore, any attempt to enforce such a provision would be a clear violation of both the UEFA Champions League and the UEFA disciplinary regulations and would therefore be sanctioned accordingly."
More top news
Goals from Charlie Austin, Dusan Tadic and James Ward-Prowse consigned Slaven Bilic's men to their fourth straight Premier League loss.
A bizarre protest against BP sponsorship at the British Museum used theatre, sea shanties and 'mermaids' to 'summon a Kraken'.
Two men have been jailed for robbing a man aged 79 as he was washing his car.