Smith broke a bone in his thumb during the one-point win over England at Dunedin on Saturday night, ruling him out of the third test in Hamilton and paving the way for Fekitoa to make a maiden start in black.
While it's not quite a sure thing - Steve Hansen yesterday kept the name of Ryan Crotty in the mix - the signs point towards the man many are tipping as Smith's long term successor at centre.
Fekitoa's displays in Super Rugby this season demanded selection in the first All Blacks squad of the year and, after beating out Crotty for a spot on the reserves' bench, he made his debut alongside Smith after replacing Ma'a Nonu at second five in the series opener.
It's another step outside where Fekitoa's future lies and Smith's injury presents an opportunity for a more immediate glimpse of what life will be like without the Hurricanes man.
The 32-year-old has a bit of life left in him yet, as shown by two solid displays so far in the series, but this weekend at Waikato Stadium appears on opportune time to lay the groundwork of a succession plan.
"We'll make that decision on Thursday," Hansen said when quizzed on Smith's potential replacement. "[We have an idea] but we don't need to tell England which one we're going to go for.
"[Fekitoa] has been playing well and it's just whether we think he's ready to start. Ryan's been there and done that, and been in the atmosphere. That's what it'll come down to - whether we think Malakai's ready to start."
Richie McCaw, for one, holds no doubts about that. Fekitoa's form at Super Rugby level has been a big reason why the Highlanders have kept pace with McCaw's Crusaders in the New Zealand conference, and the All Blacks captain is certain those performances can translate to international rugby.
"If he gets that opportunity then I'm sure [he'll be ready]," McCaw said. "He's played pretty damn well so far in Super Rugby this year - he's shown what he can do.
"He's been with us for two weeks now. He'll be up to speed with how we do things, and if he gets a chance we've all got to help him - I'm sure Conrad will, too - to make sure he's ready to go."
Smith, who will be on the sidelines for five to six weeks, still has a part to play within the All Blacks camp this week, especially if a player 10 years his junior is chosen to fill his considerable boots. While the All Blacks will miss the veteran centre's steady head on Saturday night, they know Smith will be more than willing to exert his influence in the build-up to the test.
"He's a big part of it - there's no doubt about that," McCaw said of his team's leadership group. "He's pretty calm and measured about what he sees and he's not afraid to speak up.
"So there's a bit of a hole out on the field without him there, I guess, but he's still going to be floating around to help out during the week and we've just got to get on with not having him there."
Whether a side who have already clinched the series will feature further changes remains to be seen. There must be a temptation to hand Beauden Barrett a long-awaited start at first five, while Kieran Read will also be in the coaches' thinking after overcoming his concussion issues.
"I'm not going to talk about that until Thursday," Hansen said. "Part of the reason why we don't want to talk about it is England have got to do their homework on everybody rather than just 15 blokes.
"I'd like to tell you but I can't."
