On Sleeper, we allow commissioners to remove any users from their league at any point, regardless of the reason. This is a tool available to commissioners 365 days a year.
Once a user is removed from a league, it is possible for them to re-gain access by using the original league link.
Luckily, we have a way to lock out users.
Toward the bottom of the general league settings, there's an option for Commish-Only Invites:
Enabling this option will hide and disable the league's public invite link, so any users you have removed will not be able to get into the league. They will run into this error message:
If you have any questions, please direct them to [email protected].