Well, it probably isn't a losing war.
Few weeks ago Everton did the same. Fellaini had some irrelevant WCQ game and he said: "i'm off, going to fix me wisdom teeth now so I can play with my club on saturday." He was allowed to but the Belgian association said: "very cool but we have this FIFA rule, if you go now, you won't play on saturday." Everton contested it and the FIFA bailed Fellaini & Everton out so he could play.
Depends on how bad you want to play him. It's Racing, play Marcelo and just test Ronaldo in Zurich.