Apart from the fact I assume he has never played CB, isn't a great tackler and doesn't seem all too commanding the air - great idea!
Would make more sense to put Roly back there as he has played there before; though that means taking away our biggest creative threat. Riera the other option of course.
A-Rod - 61/48 (25 games)
Siggy - 54/46 (26 games)
Dura - 56/45 (28 games)
Riera - 82/63 (27 games)
Manny - 63/52 (24 games)
Lia - 27/18 (21 games)
Roly 55/44 (28 games)
Now obviously stats don't tell the whole story but I don't think he's a bad tackler at all. I think he lacks a little bit of mongrel but in a back 3 with Siggy that might not be necessary.
I definitely agree that his aerial ability is questionable but as a starting point he's taller than any of the back 3 who started against the Cap Football XI, which is always an advantage.
And yeah he hasn't really played CB before as far as we're aware, but how much time have Riera, Lia, or Muscat spent at CB in their careers?
Agreed re: Roly though, he's too important to our attacking play for a shift to the back.
Really though I only suggested it because Ernie seems to insist on playing a back 3, and we have a lot of midfield options and only 2 natural CBs in the squad. As Jeff said it's hard to see how all our import mids fit into a 3-4-3, and I'm not convinced by any of our options for a 3rd CB in the current squad. A-Rod at least is young and might provide a long-term option if he's trained into the role and adapts to it. There also aren't a lot of kiwi or Aussie CB options floating around at the moment either.
My personal preference would still be to play with a back 4 and leave A-Rod in midfield though. Oh, and to have kept Boxall would have been nice.