Chelsea's own goalkeeper is poised to stand between them and a place in the Champions League final after the 2012 winners were drawn to play Thibaut Courtois' Atletico Madrid.
The 21-year-old Belgium goalkeeper is on loan at Atletico for a third successive season and Chelsea insist he will be free to play against them, in line with Uefa rules, as the clubs compete for a place in the May 24 final in Lisbon against Real Madrid or defending champions Bayern Munich.
It was reported that Chelsea would allow the Spanish side to play the Belgian in both legs of the semi, provided they paid a fee for each game.
However, Uefa moved to clarify that it expects Courtois to be free to face the Blues in both legs.
Chelsea chief executive Ron Gourlay said: "The loan was arranged at the start of the season and it is quite simple, Courtois can play against Chelsea, that was never in doubt.
"Regarding the Uefa statement, we will evaluate that over the course of the next 24 or 48 hours and we will comply with the rules, and he can play against Chelsea in both games."
Uefa's statement, made in advance of the draw, read: "The integrity of sporting competition is a fundamental principle for Uefa.
"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.
"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.
Courtois played against his parent club in the 2012 Super Cup, when Atletico were 4-1 winners. The match also pits Chelsea striker Fernando Torres against his former club.
Jose Mourinho's Chelsea, who beat Paris St Germain on Tuesday night to advance, play in Madrid on April 22, with the return at Stamford Bridge on April 30.
Should Chelsea prevail, Mourinho's men will meet either Real Madrid or Bayern Munich, the side the Blues beat in the 2012 final.