If there's going to be a lower limit of 1 per team, then there does need to be an upper limit of maybe 4 or 5 per team.
If it's 1 per team, then each team can have a maximum of 5 players. They can have more if more than 5 are elected by fan voting (either as a starter or as a 32nd man).
You could still have scenarios with a team having 7 in that case, but it wouldn't be as likely.