Each week, there will usually be a player on your bench who outperforms a starter in your lineup, and even though the difference in points may seem minuscule, every point counts in fantasy.
It doesn't matter if a player was your first overall pick or last, lineup tinkering is a necessity. Even some top picks should be removed from your lineup at times to avoid wasting a spot on a poor performance.
Week 1 is like the preseason for fantasy. It's when you really get to know your lineup and figure out which players have stepped up their game for the upcoming season.