Before a tournament
Roster changes are unlimited until the end of check-in for the tournament your team is signed up for.
During a tournament
Once the tournament starts, the roster is frozen — only the staff can add, remove or change roles. The roster panel has an Ask an administrator to make the change button. In the team history, such a change shows PlayZeek administration in the “Done by” column.
The match lineup is something else
A frozen team roster does not mean the same five play every match. Before each match, the captain or manager chooses from the team roster who will play — see The match room and the match lineup.
A player suddenly missing
Put a substitute in the match lineup. Looking for a stand-in from outside the team? Post a Stand-in ad on the noticeboard — but during a running tournament, adding a new person to the team roster goes through the staff.