This is the kind of stuff I'm worried about when my kids start HS, right now were in middle school and already pretty intense... I don't have any in football- but one in cheerleading, 2 in band, 2 in basketball, and 1 cross country- and they are intense! For now the rule is- you miss a practice (even if it's sickness, death in the family, whatever) you can't play or participate in that weeks game.... So, I can only image how HS will be.....
That is pretty common in high school too. You may find a little more leeway in high school for excused absences though mainly because they don't have as many kids playing. In middle school many coaches use that rule because many kids are on the team because their friends are, not because they want to be and they are trying to reinforce commitment.
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