“Depth” down the middle

I’ll admit that some of the items on the Leafs’ wishlist heading in to Wednesday’s deadline are a bit confusing to me. We’ve read that, while they aren’t in dire need of making a deal, the team is keeping an eye out for a) a top four defenceman, b) a veteran goaltender and c) a depth centre. Sign me up for the defenceman, but the veteran goalie idea is strange and I’m not exactly sure what depth at centre is supposed to be.
Are we talking Derek Roy depth, or bottom six depth? Because the Leafs just dealt a centre in Dave Steckel that fits the latter. If they’re looking to find a guy who can play up and down the lineup, then I guess Roy sort of brings that. But to be honest, I’m not sure how the Leafs could go about this.

To me, the Leafs’ "power ranking" down the middle, regardless of wingers, goes something like this:
1A: Mikhail Grabovski
1B: Nazem Kadri
3: Tyler Bozak
Penalty-killing dream: McClement
No doubt McClement is much more useful than Bozak, but I guess I’d keep Bozak as third due to his scoring ability or whatever it is he’s supposed to be doing.
If the team wants to add a centre, I’d prefer it to be another McClement-type in the bottom six that pushes Bozak out of the lineup while Kessel slots in with Kadri and Lupul, or Grabovski. If the idea is to keep Bozak with Kessel for eternity, then I don’t know what kind of centre the Leafs could pursue.
The only other scenario that makes sense is that the Leafs flip Bozak and go get Derek Roy from Dallas. A shift of that magnitude is highly unlikely, however. The Leafs would obviously have to deal futures, but Roy-Grabovski-Kadri down the middle is nice, especially with McClement doing fourth line and PK duties. If you’re going to dress two thirds of a fourth line that only plays a few minutes per game, you may as well build up those top three lines and be able to roll them as much as possible, and Roy is an obvious upgrade on Bozak.
However, there’s no guarantee the Leafs could hold on to Roy this summer if they did go down that road. Unloading picks for a couple months of Derek Roy may look bad if he walks, but I suppose there’s always risk involved in these types of deals. Plus you can ditch Bozak and have money to spend, then try for another centre this summer. 
Again, the need for a top four defenceman is obvious. But the rumors around the Leafs pursuing another goaltender seem completely off-base, and the idea of having "depth" at centre doesn’t make a lot of sense to me either because it sounds as if the team is just adding and not really restructuring.
I’m not a fan of the Leafs’ situation with Bozak in the middle of their "top line" constantly, but unless you’re making an upgrade to push him out, adding another body at centre doesn’t seem ideal.