The one thing I will add, is that in that video, all of Mata best work tends to be when Chelsea are breaking at pace and Mata is carrying the ball through the centre, with lots of space, and picking out runners ahead.
Maybe it could just be a case of thats the only kind of football that will truly suit him, and get the best out of him. He doesn't have that guile and strength on the ball like Silva, which I actually thought he did before we signed him (maybe those weeknesses were just hidden by the style of football Chelsea were playing at the time?) So in a team playing possession based football, like we've been trying to this season, and where the final 3rd is very congested, he just simply won't stand out as he doesn't have the physical presence to find the space needed?
I'm kind of hoping that LVG's long term masterplan would include quick counter attacking football, which would then hopefully get the best out of Mata.