Want to exchange hard drive in this unit

The only issue is that the hard drive I want to replace it with comes from a LaCie blade runner, and has foil over the bottom side of it where as the one I took out of it does not. Both cases are metal, but I believe there would have been no contact between the foil and the case in the blade runner, where as there may be in this unit. I'm worried about the possibility of somehow shorting the hard drive if it comes into contact with the metal casing of its new I nclosure. Should I be insulating it with some plastic or tape or something? Or am I being paranoid and should just not worrie about it?

Thanks