Mils Muliaina has found his 100th test cap one of the hardest to win.

The 31-year-old had doubts, like many observers, that he would reach the 100-tests milestone because of the recent form of Israel Dagg.

He might not have made it if Dagg had been fit - he misses Sunday's quarter-final because of a thigh injury - and it's doubtful he will play much beyond this weekend should the All Blacks advance.

"Sometimes, no matter how hard you train, you don't get an opportunity when the boys are going so well," Muliaina said. "[I was] a little bit nervous but I get an opportunity now and I want to get out there and do my job."

Sentiment should never come into team selections, especially when it comes to the knockout rounds of the World Cup, but it's appropriate Muliaina will on Sunday join McCaw as just the second player to worn the black jersey in 100 tests.

As coach Graham Henry said this morning (Friday): "He's been great servant to New Zealand rugby. He's a world-class fullback who has been a very key member of this side for a very long time so it's a special occasion for him and he deserves the honour."

It's appropriate it comes on one of the biggest stages.

Muliaina is a big-game player who will be relied on to be near his top form against Argentina. He rarely makes a mistake, reads the game well, is defensively sound and knows when to inject himself into the backline.

He's also someone who has won just about everything a top-line rugby player in New Zealand can achieve: Tri Nations, Bledisloe Cups, grand slams, Commonwealth Games gold medal and Super Rugby and NPC titles.

There's obviously one big hole in his CV and it's a large part of the reason he stayed in this country when he might have cashed in sooner.

"I think winning in 2007 would have been a good chance to finish things off," he told APNZ on the eve of the tournament. "This is the pinnacle of rugby, to win a Rugby World Cup. To have never done it before is that extra motivation. It's like a hole inside you. I definitely think I would have headed offshore if we had won four years ago."

Instead he will depart once this tournament ends to take up a career in Japan. It's the right timing. Dagg could well dominate the No 15 jersey in the same way Muliaina has for most of his career.

Muliaina has been durable and, apart from 2011 (five tests) and 2007 (eight tests), has played more than 10 tests a season since his debut in 2003.

His 34 consecutive tests (2003-2005) is the 12th-longest streak in All Blacks history but one of the more notable in the modern era.

It is also appropriate his New Zealand career will end under the gaze of Henry, who lured a young Muliaina from Invercargill to board at Kelston Boy's High School.

Henry was principal at the time but soon left to start coaching fulltime and never saw Muliaina play first XV rugby. He was also involved with the Auckland and Blues title-winning sides of 2003.

He was centre and fullback then, and had a stint at No 13 at the 2003 World Cup, but his foray into the midfield is something he looks back on with some regrets.

"It's a position I have always enjoyed but it's a position you need to be playing week in, week out," he said. "You can't afford to be chopping and changing. Fullback and centre are two totally different positions.

"If I was to do it all over again, I would love to have been able to have the opportunity to nail that position. I was a fill-in because of injuries. If I knew that was going to be my position, I would have loved to have made a better go of it. But I learned from that position and is one I wouldn't mind going back to once I have finished up and done what I want to do here."

What that is, is win the World Cup. He should take his record to 84 wins and 16 defeats on Sunday - the All Blacks' historical average is 75 per cent - and he will receive a silver cap afterwards.

Silver, of course, is something normally associated with finishing second. The All Blacks wouldn't be satisfied with that and Muliaina would no doubt trade any one of his 100 tests for a win in what he might hope will be his last - the final.