I would politely disagree with the final part mate, but yes I hear Costa struggled with disciplinary problems last season, which doesn't seem such a big deal this season.
I don't want to make it sound like I want holy than thou players all toeing the line.....but I just think when you get a player who is pretty much disruptive in area of his football on and off the field, collectively it just amounts to too much.
I think a lot of what Dr Singh mentioned about team spirit and the camaraderie amongst the group rings true. The other day Mertesacker blasted Ozil in full view of everybody. Ozil didn't try and challenge him about it, he just accepted it, apologised and everybody moved on.
It would be a shame to have a player who turned something like that into a bigger thing than it needed to be. We don't need mutiny amongst the ranks or factions emerging and I like the feeling of unity you get within the club these days. This is just a small example.