Kolo was a great athlete, played with his heart on his heart on his sleeve but he wasn't a natural defender and lacked awareness.
Dare I say, a bit like Vermaelen in that sense, just that the latter isn't as good an athlete. My problem with Vermaelen is that he has lost that spirit which compensated for his lack of awareness and won him all the love in his first season. His injury fucked him proper. It wasn't just his goals that earned him the praise, he did defend with a lot of heart.