Hansen praises centurion Nonu

All Black coach Steve Hansen has conceded that he had his doubts as to whether Ma'a Nonu would become the great player he is, as the centre prepares to play his 100th Test for New Zealand.

Nonu will become the sixth All Black to play 100 Tests for their country when he turns out against Tonga in New Zealand's final pool game on Friday.

The 33-year-old has established himself as one of the game's premier centres, and his midfield combination with Conrad Smith is one of the best on the world stage. However, Nonu was not always viewed as a player with such a bright future in Test rugby, with Hansen revealing that in 2004 he told Nonu that he was not up at Test level.

"When we first met him I think the first conversation I had with him was 'we don't think you are fit enough and we think you should go to sevens' and he went there and he changed himself," Hansen told ONE Sport.

"He is a beautiful passing centre now as well as a blockbusting runner. He has grown into a leader within the group, he doesn't say a lot but when he does speak it's right on the money."

Hansen's sentiments were echoed by Smith who has a front row seat to his midfield partner's prowess.

"He's a leader now," Smith said. "I'm sure if you asked him 10 years ago whether he'd be a leader in the All Blacks he'd have scoffed at that suggestion."

Nonu admitted that he too had not imagined that he would rack up 100 Test caps.

"It's something that I didn't think would happen in terms of playing my first Test. I didn't think I would go far looking back it hasn't been easy," he said.

"It's really been a lot of hard work and a lot of fun times."