If I was a Portsmouth fan, I would have serious reservations about this rumour.
Basically, handing a huge role to a man who has never coached is absurd. We all know the financial restrictions Pompey are under and, as much as I like the guy, he wouldn't cope with the pressure. I also believe there is time for him to save Portsmouth and to do that, they need a top class goalkeeper like him and, more importantly, a manager who knows what he is doing. James is a very good goalie, we all know that. Not many players are still playing at this level at his age but for him to manage now would be ridiculous.
Good luck Portsmouth but you'd be better off with a proper manager.