Well - maybe I should explain what I mean by negative in this case. Essentially, the di Matteo game plan was as Italian as can be: Play with a two-layered wall composed of 10 players in the back third of your side of the pitch, and absorb the Bayern pressure until they become so frustrated that they shoot from 30 yards out and miss, or bring in a cross that will be cleared.
Any attack consisted of largely blasting the ball out of the Chelsea box as far as possible and see if Drogba could run on to it. The few times they actually built from the back, they left 5-6 back behind the ball, and had at most 2 players in the box to receive a cross, or tried it through the middle in the first place.
You may recall a comment that Mata was not having a good game. Of course he didn't - his job is to build an attack, and he rarely had the ball to do so. Chelsea really missed Ramires, but even with him, the game plan may have prevented him to get in the game much.
The Dutch used a different version of negative during the World Cup Final - hit any Spaniard who held the ball too long so hard that he won't want to do it again the next time. Howard Webb nearly played into their calculations by being ever so lenient.