Daniel Carter could be out of action for up to six weeks after he was injured in New Zealand's 29-15 victory over South Africa on Saturday.
The fly-half appeared to be in pain after contact from Bismarck du Plessis for which the hooker was sin-binned, but Carter was left nursing his shoulder.
Speaking to reporters after the game, coach Steve Hansen revealed that the nature of injury would mean an absence "usually four to six weeks".
It is a further blow to the All Blacks, who are already without captain Richie McCaw, and back-up stand-off Aaron Cruden is also unavailable.
Du Plessis was sent off later in the game after he elbowed Liam Messam in the throat.
