We need an extra pivot when he is being specifically targeted with the high press. Last night the smart thing was to take Walker off, invert his replacement and use him as a pivot, much in the same way we do with Delph. Personally, i'd have replaced Walker with Gundogan, moved Fernandinho to right back (bearing in mind, he is only in that position when Napoli have the ball) and played Gundogan as the main pivot, with support from Delph and Dinho either side of him. Napoli weren't actually creating any of their own chances, so it's not as though Dinho would have been exposed on the right. Failing that we could have just swapped Walker for Danilo and inverted him as a pivot when on the ball. When our full backs invert, it is important that other midfielders drop 5 yards and it's important that Sane and Sterling maintain their width as this will still allow us to have a variety of passing options. I don't think this really happened last night, and it meant that De Bruyne and Silva's influence lessened as they saw less of the ball.