Montero is a veteran of 27 tests but has played just one match off the bench since 2016 and joins the squad to bolster the backline after fellow winger Ramiro Moyano was ruled out of the match by a rib injury.
Centre Matias Osadczuk, who won the World Rugby rookie of the year award for the 2016-17 international sevens season, had already been training alongside the squad but will now have a chance to earn a place in the matchday side for the first time.
Midfield back Santiago Alvarez Fourcade was dropped from the squad after being sent off for his club side at the weekend.
Uncapped lock Santiago Grondona was also called up after his fellow second row forward Lucas Paulos, another player named to train alongside the squad, came down with flu.
Argentina, who have already beaten Australia and South Africa this season, will play the All Blacks on Saturday hoping to record their first win against the world champions in what will be the 28th encounter between the two sides.
New Zealand are coming off a narrow loss to South Africa but can clinch the Rugby Championship with a win and a bonus point at Velez Sarsfield.
(Reporting by Andrew Downie, editing by Nick Mulvenney)
