Sometimes a coach has a team member that won't show up regularly or has other commitments. It's not fair to other team members to let this slide, so how do you handle it? Suppose a parent gets involved and demands that you allow their child to participate anyway?
Back almost 50 years ago, my high school coach had a similar situation. In that case, the team member got a job that interfered in the same way, and it was something that he wasn't willing to give up. The coach actually had a team vote while the player wasn't at the team practice. The team members voted the player off of the (Island) team. I now think it was not the best way to handle it as the coach was just trying to rubber-stamp his own opinion. He should have just used his authority. Whatever you decide, I'd now consult with the person in a position to overrule your decision if the parent goes around you or hires a lawyer.