The former Rangers star has slotted seamlessly into Chris Hughton's defensive line.
Whittaker told the Pink 'Un: "The manager has worked on that during the week and the boys knew what was needed and we have all stuck to it, and that showed in the result. We hit them on the break, put made it hard for United to create chances and we limited them.
"You do concentrate that little bit more against them, because you know if you slack off they are going to punish you. So it definitely helps you keep it tight at the back and we did that as a unit and as a squad.
"That is six unbeaten (in all competitions) and that's great, and hopefully it will continue and the clean sheets will keep coming - because we've got ability in the side in forward areas, so if we keep clean sheets then we will score goals."