New Zealand will be looking to avenge the defeat in Chicago two weeks ago
Ireland and New Zealand square off in the highly-anticipated rematch at the Aviva Stadium in Dublin later today.
The world is watching to see how the All Blacks will respond to their first loss ever to Ireland, and with the return of their first choice second-row, they will be close to full strength for the rematch.
Ireland too have added to their ranks with Sean O'Brien coming back in to the openside flank, and Iain Henderson taking his place on the bench after recovering from a shoulder injury.
It isn't easy to pick one player from the possible 46 on the combined squad listings to keep a very close eye on, but how Ireland marshal New Zealand's reserve scrum-half TJ Perenara could be the decisive factor in the outcome of the match.
Perenara generally enters the fray in the second half when the game begins to open up, and Steve Hansen trusts that he will execute the basics well, moving from ruck to ruck, firing passes left and right to keep the All-Blacks ticking over.
However, it is his support running lines which Ireland will need to be watchful of in the closing stages, in particular if it's a close contest. Every now and again, he fires out a pass from the base of a ruck, anticipates a line-break in the midfield and runs past the opposition's defensive line.
He waits for the line-break to take place and links up with the ball-player just as he is about to be tackled. He takes possession of the ball when no one else is there to defend, and usually saunters over the line for a try without too much in the way of opposition.
He did it against Ireland in Chicago, he did it for his second try against South Africa when New Zealand travelled to the republic in October and he ran an excellent line when he scored in Argentina.
Although it seems odd to highlight a man who will start on the replacements bench, keeping an eye out for Perenara's contribution could be pivotal if Ireland are to win back-to-back games against the world champions.