All Blacks fullback Israel Dagg is to undergo knee surgery that could keep him out of the game for up to six weeks, the Canterbury Crusaders said on Wednesday.
Dagg injured himself during the first half of the Crusaders' 22-20 victory over the Queensland Reds in Brisbane last week.
"Israel Dagg has had an MRI scan which has confirmed a PCL (posterior cruciate ligament) and lateral meniscal injury," the Crusaders said in a statement.
"He has been seen by a specialist who has recommended a small operation to assist his recovery. He is expected to be ready to return to play in approximately six weeks."
Fellow All Blacks back Seta Tamanivalu was also ruled out for four weeks with a hamstring strain.
The duo were among a raft of All Blacks players injured during the latest round of Super Rugby, with the Wellington Hurricanes' Nehe Milner-Skudder also ruled out for six weeks with a broken foot.
Otago Highlanders duo Lima Sopoaga and Waisake Naholo also suffered hamstring injuries last week and assistant coach Scott McLeod said there was no time-frame yet for their return.