Buderus is still being troubled by a back injury he carried through Wednesday night's Origin win over Queensland while Mullen suffered a hand injury playing for the NSW under 19 side in the curtain raiser. The Dragons are boosted by the return from suspension of Luke Bailey but star trio Jason Ryles, Matt Cooper and Mathew Head remain sidelined by injury.
The Knights thumped the Dragons 54-6 in their round six clash in Wollongong earlier this year.
North Queensland's five State of Origin players must prove their fitness this afternoon for Saturday night's NRL match against Canberra. Luke O'Donnell expects a thumb injury will keep him out but it's a brighter outlook for Matt Bowen, Carl Webb, Matt Scott and Johnathan Thurston.