Update select content?

Hi it is possible update content of select field without submitOnChange?
I have 2 selects fields. First is list of sport teams and second his players.
For teams i have 'foreignKey' and 'submitOnChange' and for players 'options_callback'.
But this solutions have 2 problems.

1. Uncomplete record is saved without mandatory fields if i change team.
2. Error 'Invalid input' if any player was selected before team change.

THX for help.

Try this: https://github.com/terminal42/contao...onalselectmenu