For me you only rotate 3 - 4, 5 at a push players game to game (regardless of competition), don't like this 1st XI 2nd XI malarky. So to keep players fresh but still strong 1st XI i'd go:
Howard
Coleman Stones Jagielka Baines
Besic Barry
Mirallas Osman Atsu
Lukaku
Osman?!?!?!?!?! Well Europa is slower than premier league and he'd have pace around him in that line up, McCarthy's looked off the pace so barry and Osman hopefully can be a calming influence on Besic on his first start, plus we need to see Atsu sooner rather than later. With the above line up you can take lukaku off for Eto'o if were comfortable 2nd half, and bring in Naismith, Distain, McGeady, maybe Gibson (if he's fit) and start Eto'o against palace at the weekend.