does the old stamina trick still work from pes5? you should try going to formation settings not just before a game, you know in the space between games then sub all your starting line up to the bench. then in the formation settings before the game itself you switch your starting lineup back into the right places. sounds like a long ting but it used to bypass all stamina problems on pes5 haven't tried it on pes6, give it a go, hopefully all your starting 11 will have full stamina for the next game no matter how much you run them down.