There's no clause, there's a "gentleman's agreement" and their chairman is a massive d****ead so there's no guarantee it'll be upheld. He's on a free in the summer of '26 so people might just be holding off til then. He was also a bit of a wayward soul for a while which might be putting people off. He broke into the Lyon side at 16'17 with a bang and people were talking about him like he was going to be the next Zidane but he fell off massively for a while, got a reputation as being a bit lazy and having an attitude problem. It's only in the last year/18 months that he's started to really blossom. Apparently his attitude issues were massively over-exaggerated