How poor were their centre backs?

I thought that we'd seen some rubbish already this season, but those two today were the worst I've seen for a long time. Right at the end they were both going for the same ball in the air and for a moment it looked like they were going to cap their games off by knocking each other out. Seriously though, they were rubbish. Not taking away from Macken or Hume, who made them look even worse.