All Blacks lock Ali Williams has been ruled out of the third test against Ireland at Waikato Stadium next Saturday night because of a knee injury.

The veteran second rower, who has made 75 test appearances, will not be replaced in the squad which is scheduled to fly from Christchurch to Hamilton this afternoon.

With Sam Whitelock and Brodie Retallick starting the first two tests, Williams was used as a replacement in the Auckland and Christchurch tests but exacerbated his knee problem when he replaced Retallick in the second spell of last night's 22-19 win at AMI Stadium.

''Ali will be going in for an operation this week on his knee,'' All Blacks coach Steve Hansen confirmed. ''He has got some articular cartilage damage in his right knee which has been causing him some problems.''

Williams will be sidelined for ''six to eight weeks minimum'', he added.

Hansen will now employ Luke Romano, Whitelock and Retallick as his locks for next Saturday night's match at Waikato Stadium.

It is hoped Williams, 31, will be fit for the Rugby Championship series that now includes Argentina. The All Blacks' opening test of that series is against the Wallabies in Sydney on August 18.

Williams is the second player to be withdrawn from the squad after loose forward Victor Vito succumbed to a knee problem following the 42-10 win in the opening international in Auckland.

Vito was not immediately replaced in Christchurch but Liam Messam will join the squad at training this week.

No 8 Kieran Read, who was replaced by Sam Cane at halftime on Saturday night because of a head knock, is no certainty to start the third test.

Hansen said his health would be monitored.

''Everyone else is obviously bumped and bruised and sore but fit for selection,'' Hansen added.

Williams had been selected in the squad to bolster the experience among the locks but that responsibility will now be handed to Whitelock who has played 27 tests since his debut against Ireland in New Plymouth two years ago.

Whitelock, 23, acknowledged that following Dan Carter's late drop goal in the final minutes the feeling in the All Blacks camp was more relief than elation.

''It was probably a bit of that towards the end,'' Whitelock said.

''It was a little bit frustrating there for a while and obviously it was a close game. To get the win is great. It is a real big credit to the Irish side. They started well and kept coming at us, so I think the way they showed up was very impressive.''

- © Fairfax NZ News