My mutant

[sasha m]

Ok but why they re doing that ? (I mean only for asso games)

in asso game you don't gain any skill. keeps gray down. keeps overall down.
other competitions you use substitutes and reserves. them you train for additional positions and special abilities, so they don't gain stars or % either.

now, since last week, game considers your best 14 players, regardless where they are (even injured). i guess before that it was starting 11. so you'd put your 3* 40% players in, get easier opponents, switch to your real top 11 after that and rule them.