There are always a few hundred tickets allocated to the visiting team. I *think* the Panthers will use some of those on sending team employees and players family. I think the rest may be available thru some partner sports tour company. I have never seen an individual able to get these directly. Not totally sure on how they are used though. I do know Arizona returned a few hundred of their allocation for our game which was a good sign they weren't going to have any fans here.
I am confident that you won't be able to get a ticket at face off ticketmaster unless you are located near the home team.
Online sites such as stubhub/ticketexchange or a sports tour are the best way to get tickets but will be expensive.