I think it has already been said (and proven?) a couple of times that the GE (game engine) recognizes the unassigned SKP, even if you don't assign them by yourself.

And even if it "worked", it would be a pitty that after a couple of season where you just saved, saved and saved and finally applied the SKP on your players - to be eliminated in the early stage of the CUP (since nothing can guarantee you a semi-final or final spot).