Not only will it depend on the coach, it also depends on the sport. Swimming coaches personalize workouts and it’s not hard to show up late or even outside of team practice to knock out your yardage. A water polo player, however, probably can’t practice alone.
With that said, @Midwestmomofboys is right – many D3 have blocks of time in the afternoon when no classes are scheduled so that this won’t be an issue.