This is a weird situation, which you may have to do something like creating a set of 5 circular groups, with each player being a key player in one of them.
i.e:
Group 1: If player 1 is picked, use player 2.
Group 2: If player 2 is picked, use player 3.
Group 3: If player 3 is picked, use player 4.
Group 4: If player 4 is picked, use player 5.
Group 5: If player 5 is picked, use player 1.

You don't actually need to only use 1 player in the secondary part of the group, you can make it so that it says: if player 1 is picked, use players 2,3,4,5 etc... But I'm not sure exactly which is faster in terms of compute time.

This is the only way I can think of that will give you the all/or nothing constraint you're thinking of.