All Black coach Steve Hansen has put the form struggles of Blues' loose forward Steven Luatua down to poor fitness, saying he goes "missing" in games too often because he isn't capable of repeated hard efforts.

It was a harsh message accepted by the 23-year-old yesterday, a day after he was pushed to near exhaustion at the end of the All Black training camp in Christchurch.

While the rest of the All Black hopefuls focused mainly on recovery, Luatua was left hunched over and gasping for breath after being put through a running and circuit ordeal, which included heavy rope work, by Hansen and trainer Nic Gill.

Luatua has again been unable to break into the Blues' starting line-up this week, coach John Kirwan preferring to play Peter Saili at No8 for tomorrow's match against the Sharks at North Harbour Stadium, with Jerome Kaino on the blindside and skipper Luke Braid returning from a shoulder problem to the No7 jersey.

Of the Blues' last three games, Luatua was started in only one - the loss to the Chiefs - after Saili withdrew to be at the birth of his daughter.

In an honest and revealing interview on Radio Sport yesterday, Hansen explained why Luatua was singled out by himself and Gill.

"Steven's problem is that he's probably been a bit lax on the aerobic side of his game, so hence he's not doing enough when he's out on the park.

"He'll do something and then go missing for five or six minutes. You want your players to be doing repeated efforts and he's just not doing that at the moment so we had a bit of a chat about that and put something in place during the camp to feel what it was like to be able to hurt and still deliver what he needs to deliver on."

Luatua made a big impact last year in his first full season of Super rugby, his form for the Blues resulting in an All Black call-up and 11 test caps, but he has been inconsistent this season.

He said he acknowledged Hansen's message.

"What he's found this season and the feedback I've got is that I go missing in games. Part of the reason why I go missing in games is because I'm not fit enough, so [that] was just coach being coach. He said "this is how you get fitter and this is how you have to hurt during training so you can hurt during games'.

"I didn't take it personally. I thought my fitness was good but obviously not good enough."

Luatua's ability to play lock makes him a potentially valuable member of the All Black squad.

Eight players are vying for the loose forward spots, but Luke Whitelock, who is not required for next week's camp in Wellington, should be an early casualty when the squad for the England series is cut to 31. Victor Vito may also be vulnerable. Luatua is nervous about making the final cut.

"Obviously I'm grateful to be there but there's still unease that I'm not in the team yet."

In the running

All Black loose forward hopefuls:
• Richie McCaw
• Kieran Read
• Liam Messam
• Jerome Kaino
• Steven Luatua
• Victor Vito
• Sam Cane
• Luke Whitelock.

- APNZ