Cape Town - All Black flank Ardie Savea said he is working on getting heavier to be more effective at ruck time.
The nine-Test All Black is seeking help from a nutritionist to get bigger as being an openside requires a physical presence.
"Around the breakdown, being stronger over that and obviously with my weight getting heavier - that will help me physically," Savea told the Stuff.co.nz website.
"Mainly around that breakdown, moving bodies and being strong over the ball. I am working hard with the nutritionist and finding ways to put on that weight."
Savea, who weighs around 100kg, went on to say that competition in the team helps each player get better.
"It's a good thing, whenever each one of us plays well. It pushes us - And that's good for the team."
New Zealand will take on Ireland on November 5 at Soldier Field in Chicago, United States.
On their year-end tour, the All Blacks are also scheduled to play Italy (Rome, November 12), a second Test against Ireland (Dublin, November 19) and France (Paris, November 26).