You could simply train them in scrimmages.
Or you can put them as a PG on offence, but play them as a Center on defence. That way they won't cost you games as much because they still play all defence as a center, and if they have decent jump shot and secondaries they will do okay at PG.
If you are worried about it, just train Passing in weeks where you have really tough matches that you can't win, or really easy matches.