It is the same formation as against Napoli, though you are right DC offers something completely different on the left than Matuidi. I believe Allegri wants the team to be more on the ball and play with periods of higher pressure, also to avoid the greeks from having the initiative and getting momentum from fans etc. However, he may have other reasons. Let's just hope that we are able to keep the ball rolling, because if we can play out of pressure for the first 30 minutes, i believe we have a good chance at winning the match.