Kanter's not in game shape yet. That's pretty obvious if you watch him. Even when he is back in shape, he'll probably never be a good defender. But also imagine what the C's are going to be like offensively with Hayward back and a healthy Kanter who has great hands, can score and is an excellent rebounder. This will be the best scoring team in the league and last I checked you win the game if you outscore the opposition.
I may be in the minority but I think they can get by with the current roster of centers. There are plenty of fouls and their individual skills are all useful. Plus Williams has really improved so the overall talent level there is higher than probably most of us anticipated when training camp opened.
