Why can't I pick the jersey size I want when confirming an invitation?

Do note that the jersey sizes available are linked to the jersey number you will wear in Pro-Circuit events.

Thus only specific combinations are available and in case the size / number you want is no longer available it means another team member already picked this combination.

Possible combinations are:

Once those are used the 6^th player of a team confirming an invitation can pick:

You can contact 3x3roadtoworldtour@fiba.com in case you want to swap sizes / numbers with another player of your team.