Colin Slade is in repeat injury rehab, but he is the natural five-eighths deputy for Daniel Carter at the World Cup.

All Black great Andrew Mehrtens offers that view from France where he is still playing and watching enough Super 15 rugby to gauge the contenders.

He believes Slade, Aaron Cruden and Mike Delany are the most fluent five-eighths while Luke McAlister and Stephen Donald play like midfielders asked to perform other roles.

That happens tonight when McAlister and Donald duel in the No 10 jerseys in front of the All Black selectors as the Blues and Chiefs go at it on Eden Park.

Mehrtens was buoyed by the choices and their range of talents, they were all strong players who suffered by comparison with the peerless Carter.

"People talk about the gap but that is in the world, the gap between Carter and the rest," he said.

"You tend to lose sight of the fact we have some quality guys there lining up behind Carter. In comparison to Carter, everyone else pales and the All Blacks have been well served by his longevity too."

Slade's test CV reads just 19 minutes as an injury replacement for Cruden last year in Sydney before both missed out to Donald for the end-of-year tour. Slade's blighted rugby experience this season is three games for the Highlanders, one pre-season match, a club game and two broken jaws.

"I judge 10s on the feel you get for them," said Mehrtens, a 70-test All Black. "I really think it is an advantage for Slade that he has played in other positions like fullback and wing, because you can use your energy and read the game with a bit less pressure from those areas.

"The games from 10 and 15 go a wee bit hand in hand. He has played fullback and played well there.

"He has got gas, he is courageous, he has a good feel about him. He will be back soon."

Cruden was more a stepping style player, said Mehrtens, someone whose instincts were to have a go, to lead the attack and have teammates run off his probing style.

"He did that so well for the Hurricanes when they needed it badly last week.
He is still very young, he was thrust into the top level early, but he has the ability to really control and vary games.

"The more he plays, the more his kicking and variety will improve."

Delany appeared to have dropped from favour with the Chiefs this season, but Mehrtens liked him in the pivot role. He was unspectacular, said Mehrtens, and the worry was he was going overseas when he was still only in his late-20s. From that age and into their early-30s, five-eighths matured and showed their experience, said Mehrtens.

"I'd like to think he is still in the mix. He went away with the All Blacks in 2009 and did not do anything wrong there."

McAlister had all sorts of talent and had shown his versatility when picked as first five-eighth for his test debut in 2005 against the Lions, said Mehrtens.

"I think he benefits and plays his best when he has more width and room. He is always a threat, but does not look like a natural organiser," Mehrtens suggested.

Donald was very direct, courageous, tough and gutsy. "I liked it when they played him outside Carter, I thought the idea had merit though I don't think it went too well.

"I think it helps Carter to have a playmaking 12 outside him rather than a bashing 12.
The attention Carter is going to get from any team will be huge. So I think it helps to have a 12 who can step in, call for the ball and organise things as well. It creates more balance."

Whatever decision the All Black selectors made about Carter's backup, each candidate would qualify as team men who would boost the team spirit.