First of all, we not only can, but we must play our first choice players in these three games, else no chance of winning them, simple as that! Why should we not play them? I would argue we need to play them as they need to gel better and if anything they are not getting enough games.
If I had to choose between the two Chelsea games I'd choose the 3 points, a Champions league place is our target this year and we must stay focused on that. The cup would be nice to win, but thats all, a 4th place finish is more important for the future of the club.