All Blacks: Hamstring opens door for Luatua

Messam's troublesome muscle has given his replacement a chance to prove a genuine contender for blindside role

In the alternate universe Liam Messam no doubt wishes he was currently occupying, he'd have been named to start at blindside on his home patch tomorrow.

The expected physicality of the Pumas would provide him with another opportunity to show that rough and tumble is his bag these days - that he's much further down the track towards being the intimidating force the All Blacks want from their No6.

But instead, fate has forced Messam to live with the less palatable reality that he's now in a genuine scrap for the jersey. That hamstring of his, which tightened and pulled before the first Bledisloe Cup clash, has had more effect than a muscle should.

Messam's absence has enabled Steven Luatua to answer some key questions earlier than the coaching staff forecast. They have discovered in the last two tests that they have an athlete with the mental capacity to cope with test rugby. That's always a big box for any player to tick.

More than just cope, though, Luatua has contributed beyond expectation. There were periods in both Bledisloe tests where he was like a plane traversing the Bermuda Triangle - intermittently flickering on the radar, threatening to disappear altogether.

In Sydney there was a bit much walking, hands on hips, chest heaving, brain clearly wondering if it was in charge of a machine designed to handle the pace and intensity of international rugby.

But in Wellington there was much less of that and considerably more of the Luatua who impressed so much during the Super 15. His memorable burst through the Wallaby midfield and slick handling were vital components in both Ben Smith's tries and confirmation that he's comfortable in open spaces.

The Pumas will determine his appetite to play in dark spaces, which is of considerably more interest to the coaches and most likely to have a profound impact on Messam's medium- to long-term future.

As reassuring as it was to see Luatua run and pass like a giant outside back, that skill wasn't much in doubt. Throughout the Super 15, the selectors kept seeing room for improvement in his leg drive when he made contact as both tackler and ball carrier. They wondered whether he could impose himself physically in an arm wrestle and whether he could look the same world-class prospect on a wet track as he does on a dry. As managers in English football say, "Can he do it on a Tuesday night in Stoke?"

Argentina like to make similar interrogations of loose forwards. Supposedly the Graham Henry influence has encouraged the Pumas to embrace a more expansive game. In the first 20 minutes at least, though, self-preservation will be their top priority and Argentina will prove again there is no more patient side: they will advance inch by inch, affording the ball a meagre five-metre radius to roam.

They haven't been averse in the past to a bit of literal jiggery-pokery - the kind that leaves opponents blinking a lot - and Luatua has the chance to make Messam yet more uncomfortable and twitchy if he can play as impressively against the Pumas as he did against Australia.

The Messam-Luatua battle was inevitable but until that hamstring it probably wouldn't have started until later this year.