Rumours circulated on social media that the ex-France international, now playing with Lokomotiv Moscow, had gone to the Middle East to join the uprising against President Bashar Al-Assad.
"[Lassana Diarra] denied in the most formal, the most categoric, the most absolute fashion that he has gone to Syria," his lawyer Eric Dupond Moretti told AFP.
"He has never set foot in Syria. It's absurd. He is not a jihadist, he's a footballer for Lokomotiv Moscow."
Diarra had already taken to Twitter to brand the rumours as a "joke" at the beginning of the week.
In Syria??? Lol nice joke guys have a good evening on twitter G5!!!!— Lass Diarra (@Lass_Officiel) April 7, 2014
Diarra spent three years at Real Madrid after leaving England and plied his trade for Anzhi Makhachkala for a season before his move to the Russian capital last summer.