That's not how Fantasy Football works. You can't change your roster once your players' games start. The tracking is real time through any decent fantasy site (ESPN, Yahoo, CBSSports, etc). Highlights have nothing to do with fantasy, especially within the context of bbeagle's comment about getting some advantage from watching day old games. Fantasy Football has almost nothing to do with actual teams. FF is about individual players. Seeing them the next day does nothing.
Seeing how they play will let you know for the upcoming week on whether to start them or not. More insight.