thanks to all to answers.
I decide to lose first round of cup because the game was vs not bot and I did not want some injuries. I want to promote and the cup is only a "risk" , and benefit is too small (50K for win).
On this skill, I had always 4 or 4,5 balls, in all seasons of the past. But, how I wrote, I never relegated in my life, only last season for the first time. May be the combo "relegate + no cup" has a 1 ball max for this skill.