If he is ruled out the All Blacks will need a like-for-like replacement to back up Sam Cane and that is likely to be Latimer, who has been preferred ahead of Cane at the Chiefs this year.
Latimer played five tests for the All Blacks in 2009 but hasn't played for the national side since, despite some impressive Super rugby over the past few years. He was a standout for the Chiefs during the latter part of the 2013 season as they defended their title and has continued his good form for a struggling Bay of Plenty ITM Cup outfit recently.
"I've certainly got my fingers crossed for him," Bay of Plenty coach Kevin Schuler said.
"He's been great, he came back and had a rest at the start of the season - we didn't see him for a few games - but he's been going very well. He's very reliable and very consistent. I think the other thing about him is that he can handle any type of pressure or situation. He can play his game under any circumstances."
The injury to Todd, who made his test debut this year against France and also came off the bench as a substitute in the All Blacks' 29-15 victory over the Springboks at Eden Park, has continued a recent bad run for New Zealand No7s. Luke Braid has been struggling with an ankle sprain for Auckland, while Karl Lowe yesterday sprained a hamstring in Hawkes Bay's 18-9 defeat by Tasman in Nelson.
Nineteen-year-old Ardie Savea impressed during Wellington's recent victory which maintained his side's unbeaten record this season, and while he has been mentioned in dispatches by All Blacks coach Steve Hansen, he is likely to be considered too inexperienced for a call up to the next level.
Todd's Canterbury teammate Colin Slade also suffered a potentially season-ending injury when leaving the field with a knee problem on Saturday.
The All Blacks will over the next few days concentrate on recovery after spending 15 hours travelling from Auckland to the Argentine capital.
McCaw injured his knee in the first Rugby Championship test between the sides this season - a 28-13 victory in Hamilton a fortnight ago.