Actually not a good idea, no off-side in the defensive half!
There was an old joke that went around in the mid-80s:
Who would win if Maradona played Wolves? (Wolves were particualry bad then)
Everyone said 'Wolves', but then the smart-ass would say, 'yeah but what about offside?'
HOWEVER, the player in possession cannot be offside and passes backwards are not offiside.
I honestly thought that everyone knew that the keeper qualifies as a defender . . .