Last minute formation changes / rest using disavantages?

[ibangali]

In my case, I alway keep my team as 4-1-4-1, my team go to the field with that formation, but just before the whistle blow there few sec cool down time and on that time I change the formation on field (I never had to change players as all are 3 positions except GK) to counter oppo and click "save" as soon as whistle blow, in that way I never had problem but last 2 seasons I got troll, even my team was 115% oppo 65% but I never think about that its happening due to last min formation change. Interesting...
Even I notice my assigned FK sp player doesn't do fk, every time different player take the shot, very interesting...
(although my main team with one of AC team not playing now)