Why does everyone keep saying that Banega's eccentric ways don't impact him on the pitch? Of course they impact him on the pitch. He's extremely inconsistent. And when he is bad it's not just that he has a quiet game, he's horrible. If he played like the way he does on the YouTube highlights all the time there's no way he'd be available to Saints for this price.
Plus you know, he ran over his ankle with his own car. So I would say missing a season of football counts as impact on the pitch.
At the reported price and and given his potential, he still may be too good to pass up but signing him is a pretty huge risk, IMO.