Editor pre-game help

Hi!
What's the difference in the pre-game editor from PA and maximum PA.

Example...Fagioli, Juventus FC
CA 129
Maximum CA 129
PA 155
Maximum PA 145

or, always in Juventus FC, Miretti
CA 132
Maximum CA 132
PA -9 (from 150 to 180)
Maximum PA 115

Why is maximum PA less then PA? Can someone explain me? It's the first time in pre-game editor...