The versatile loose forward has played a much tighter role for the Chiefs in the Super 15 this season, filling in the back-field defensive role and other covering duties even though he was often wearing six on his jersey.
One of the demands from the new coaching group who came to the Chiefs was that Messam tighten his game and become more effective in the inside channels instead of ranging out wide so much. If he wanted to add to his nine tests caps they suggested he aim for the sort of game Jerome Kaino produced.
Evidence of Messam's altered style has been seen at the Chiefs, while his workrate, skills and grit remain unquestioned.
So if the head knocks which have lowered Kieran Read and Adam Thomson continue to trouble those loose forwards, Messam's case for a test start in Hamilton will grow.
His ability to cover all three roles means he is more likely to be used from the bench but injuries give the All Black panel the option of rejigging their loose forward formation.
Sam Cane could stay on the openside where he made a useful start in the polar conditions in Christchurch and captain Richie McCaw could make the move to blindside. That would still allow McCaw to perform the work he does now, the fetching, tackling, stealing possession and ball-carrying which saw him with double the carries of any player in the second test.
When Read has been out of commission for the Crusaders, McCaw has been used at No 8 but he does not look anywhere as comfortable, natural or instinctive with those duties. Stick him on the open or blindside and his work flows much better, he can operate in areas where his reputation has been embraced in 105 appearances.
His reactions and instincts around and over the ball are precious and he could still employ those in a tandem operation with Cane who looked lively in most areas of his test introduction.
While a Messam, McCaw, Cane grouping will decrease the loose forward experience, they will not have to contend with rugged Irish No 8 Jamie Heaslip, who has broken a finger and will miss the third test .
His absence will hurt Ireland's cohesion, while if Cane and Messam start they will feel attuned on their home track in front of their own crowd in conditions which should be more favourable than the cold of Christchurch.
When coach Steve Hansen was asked about Messam missing out on the initial squad selection, he said the selectors knew about the Chiefs loosie, they had a full dossier on his ability.
It did not seem to bode well with Luke Whitelock and Brad Shields making the group ahead of him. But with the rising injury predicament, Messam has leapfrogged that younger duo and could even vault into the starting XV.
