Have a Lyon supporting friend that has been raging about him constantly, now I've seen some Lyon matches with this friend and I can certainly see what he is on about.
Not premiership proven or anything, but from what I saw he would be an upgrade on Herrera, and at the bare minimum healthy competition for him. Physique wise he is superior to Herrera, also his passing range and goal threat are better. As I've stated previously he loves his interceptions as well and doesn't shy away from defensive responsibility.
No rumours about him though, read that Juventus were interested and I deffo think that if we let this one slip it will be another steal for Juve.
We'll need both a DM and an addition b2b if we are to continue this 3 man midfield thing, actually just playing 2 mids we still need two mids since Fellaini can't be anything else than a battering ram and last ditch solution.
I have no actual idea about Fabinho since I've only seen him against City, not seen enough to form an opinion but just threw his name out there since he seems to be in vogue at the moment, and quite frankly there isn't any available standout DM's around that are available.