Is this fair play (streaming)?

I'm in a head to head baseball league and we're in the playoffs this week and next. My Thursday lineup was poor -- all my players were off. I decided to drop all of my mid-relievers and add more hitters so that I could staff a nearly complete lineup on Thursday. Then I dropped the hitters after Thursday, and picked up new mid-relievers. Several others in my league were upset and said it wasn't fair play. Do you agree?