I think Roberto wants a little more possession and tracking from the wing players in the first half. This lineup hopefully allows for Baines and Coleman to be more involved and require Arsenal's wing players to be mindful of Coleman and Baines to work harder defensively. Then we bring in Geads, Gerry (certainly) in the second half when they have expended energy and Ross (if needed). Naismith is a better partner for Lukaku than Barkley up top and will work better in link up play. I think Roberto would be happy to not use Barkley today given the calf.