New Zealand are facing a potential scrum-half crisis ahead of Saturday's return Bledisloe Cup match against Australia in Auckland.

Andy Ellis and Jimmy Cowan were both injured during the All Blacks' disappointing 34-19 defeat to the Wallabies in Sydney and are in doubt for next weekend's clash at Eden Park.

All Blacks discard Piri Weepu is the obvious player to call upon as cover but if both Ellis, who has damaged ribs, and Cowan, who has a broken nose and a knee strain, need to be replaced, half-back stocks start to look a little thin.

Below Weepu, New Zealand's leading half-backs Jamie Nutbrown, Alby Mathewson, second string New Zealand Maori half-back Chris Smylie and Taniela Moa have minimal international experience and the absence of Byron Kelleher (overseas) and the injured Brendon Leonard is keenly felt.

Ellis and Cowan will be reassessed on Monday, when any replacements are likely to be named.

New Zealand will need to be ready for another battle against Robbie Deans' Wallabies, who top the Tri Nations standings after two wins from two games and who are likely to have captain Stirling Mortlock back.

All Blacks captain Richie McCaw has been back running for the past couple of days but no decision on whether he will make his comeback at Eden Park has been made and he will be assessed on a day-to-day basis.