Newcastle playmaker Jarrod Mullen will undergo surgery on his troublesome hamstring and has been ruled out of NRL action for up to 12 weeks.

Last-placed Newcastle got the bad news confirming a ruptured hamstring tendon on Friday after Mullen suffered the injury in the Knights’ loss to Manly 11 days ago.

“After a follow-up review appointment with the specialist on Friday morning, Jarrod Mullen has been booked in for surgery on Tuesday,” said the Knights in a statement.

“Mullen’s treatment will be conservative until at least a progress appointment next week with the specialist,” it said..

“He is expected to be sidelined for 10-12 weeks.

The Knights next meet Cronulla on Sunday week at Hunter Stadium.