If there were no rookie involved and we were choosing between Battle and Ziegler for the 5th spot, I think you go with Battle because of his special teams ability-- better to have a guy who can contribute than one who just rides the bench. Plus, Ziegler is more likely to accept a practice squad role.
Assuming there is a rookie WR chosen and he does show the ability to contribute (even if just on special teams initially), he's got to be given that 5th spot. In that case, I expect Battle would be moving on, because I can't see him accepting a practice squad role. Ziegler on the other hand ends up on the practice squad in either scenario, an injury away from a roster spot.
[ Edited by gravelburn on Apr 2, 2009 at 3:54 PM ]