The work that the team would have to do should be design with contingencies in the event of a member suddenly not being present. Some of the things I have seen in y experience is have very open dialog in team meeting about scheduling the work in advance. That way it can be adjusted if anyone have a vacation that they would like to plan. In the event of sudden emergencies, where a teammate is suddenly absent and their work need to be don’t in a timely manner; the other member would have to member will have to split the work. The point of having a good team is to be able to cover each other back when the team should work as one large system made up of individual parts.