Does some good things, but makes more than his share of mistakes too. He's there though for his run, something which we lack out of the back half. Take him out and you have to replace it, in which case McKenna is the only real option.
I rate McKenna, and think he will be a very good player for years to come, and his dash and kicking out of the back half is much better than Gleeson's. The other option is Dea. What he adds is a bit of defensive stability we could do with, and some intercept marking.
Personally I'd be looking to change the mix. Hurley is still to properly hit his straps and until he does we have to make up the difference. I'd be inclined to replace Hartley with Brown. Hartley has been good, but he's a purely defensive player whereas Brown offers a bit more footy smarts and intercept marking.
As it stands our defence is the area of the ground that concerns me most right now. We got scored against too easily last night, and I'd kill for a Rory Laird type who could generate quality run and carry from the back half. It will improve, but in the meantime have to get right the mix between stopping the opposition and creating attacking opportunities.