"It will certainly be different to those two games. I've played in front of 48,000 of their fans, and it will be different on Sunday, when there's 52,000 Geordies screaming us on.
"It was great to be part of it at the Stadium of Light, and it will be the same on Sunday."
Fans are almost split down the middle in the East Durham village where Harper grew up.
He added: "Easington's probably 60-40 Sunderland.
"There's quite a few Geordies there, but they are outnumbered. However, they're a vocal lot, and the rivalry's good. I still go back to my mam and dad's all the time, as they still live there."