There was no way that was Vlaar's fault. I'm not sure how you think we would have been able to stop the goal if he hadn't at least try to intercept the ball that put Sturridge in on goal. Okore got pulled out of position and failed to track him back into the box.
I thought the defence was generally a lot better today, look more solid with Vlaar and Okore in the centre and Luna on the left. Our problem today was one we've had for years, we don't have enough creativity to unlock defences at home.