STAR North Melbourne midfielder Ben Cunnington will be sidelined indefinitely after having surgery to remove a testicular tumour. 

The tumour was discovered on Monday and Cunnington underwent a successful operation to have it fully removed on Tuesday afternoon. 

North's general manager of football, Brady Rawlings, said the club was supporting the 30-year-old and his family as he recovered. 

"This has all happened very quickly, but our focus is on Ben and his family right now as they deal with this news and allow him to recover fully," he said.

"From the diagnosis earlier in the week up until this point, we've moved quickly to ensure Ben is in the right hands medically and that he and his family have the right support around them.

Ben Cunnington in action against Carlton in round 19, 2021. Picture: AFL Photos

"We ask that everyone respects Ben and his family's privacy as this is a private health matter.

"Due to the sensitive nature of this news, we ask that the same level of respect and privacy be afforded to Ben's wider family, friends, teammates, coaches and staff."

Cunnington has been in excellent form in recent weeks amid the Kangaroos' improved run of form, and racked up 27 disposals and nine clearances in the Roos' stirring win over Carlton last Saturday.