All Blacks fullback Christian Cullen is to have surgery next week to remove bone fragments from the back of his right knee and will miss the three Philips International Rugby Series tests against Samoa, Argentina and France later in the month.

All Blacks doctor John Mayhew said Cullen would see orthopedic surgeon Stu Walsh on Monday and have surgery the next day. He is likely to spend time with the All Blacks squad after his operation so medical staff can oversee the start of his rehabilitation programme.

Cullen had been below fitness for several weeks with a sore knee and a scan yesterday revealed the problem after two weeks rest failed to produce the expected improvement in movement.

Cullen tops the list of a number of injuries being carried by members of the National Training Squad, who are in camp at the adidas Institute of Rugby in Palmerston North.

Tana Umaga, Byron Kelleher, Jerry Collins, Mark Ranby and Leon MacDonald all sat out a physical training session late on Saturday afternoon.

Umaga and Kelleher both have calf strains suffered during training last week; Collins injured a shoulder playing club rugby; Ranby is battling with an ankle injury which flared up towards the end of the Telecom Rugby Super 12 while Leon MacDonald is making a gradual return to rugby following recent ankle surgery.

Aside from Cullen, the injuries are not likely to prevent players being considered for the test against Samoa at North Harbour Stadium on June 16.

In Cullen's absence, MacDonald is likely to be first pick full back , but with the doubts about his match fitness Auckland's Doug Howlett may come into consideration.