Here is what he said on The Dan Patrick Show:
"I think, the thing with Rondo... late in games it becomes 4-on-5 in the half court. You know, Kobe was guarding Rondo and basically just sat in the middle of the lane and blew up every set that Boston was trying to run, and I think it gets frustrating for the Celtics. As good as Rondo is... in the half court, it does become difficult to execute offensively..."
A few moments later, Patrick asked, "could you make him a better shooter?" To what Kerr's response was, "No, I don't think so."
This isn't a hater talking. This isn't a guy who has a beef with Rondo or the Celtics. I personally agree with Kerr and I think it's going to be a huge problem in the playoffs against smart teams.