Prove he is fat. Simple, you can't. Just because he might be bulkier than previously doesn't mean he is fat. He's still a professional player playing in the top division in the country, still scoring and getting assists from one of the top 2 clubs.
What's the point of ignore if you can still reply to me? Regardless, that's more likely down to his attitude and behaviour, not his fitness.
He's still a professional athlete that's got 16 G/A this season.