Cane has played 80 tests and captained the All Blacks on 13 occasions.
But there is speculation New Zealand Rugby, acknowledging something has to be done to shake up a misfiring team, possibly no longer believes he is the right choice as captain.
Whitelock, a guaranteed starter when fit, would have the experience needed for the role if Cane loses the captaincy.
The potential changes comes in the wake of the All Blacks losing four of their last five tests and their first home series defeat in 27 years.
New Zealand Rugby bosses and the All Blacks have gone to ground since last Saturday's third-test loss to Ireland in Wellington but Foster is set to break the silence on Friday afternoon.
The All Blacks squad naming for the Rugby Championship - that is expected to usher in a number of personnel changes - has been delayed until today to buy New Zealand Rugby time to determine how to address the team's deeply-concerning form slump.
But with the All Blacks scheduled to gather for a camp in Wellington next week and then depart for two tests against the Springboks in South Africa, starting on August 7, D-day is here.
The reason Ian Foster's press conference was cancelled
Today's press conference comes after one was abruptly cancelled on Sunday following the weekend defeat to Ireland in Wellington.
All Blacks communications manager Jo Malcolm has said on social media it was her decision to cancel the media briefing at the last minute.
Writing on LinkedIn, Malcolm said: "For the record, I decided not to demand that All Blacks head coach Ian Foster front late on Sunday morning. Not him. I felt he needed a day or so to work out what he wanted to say and not just be a punching bag for the media, who let's be clear, wanted blood."
It is customary for the All Blacks coach to talk to the media the day after a test match to share with the public their views on the match. This briefing was cancelled without notice on Sunday, leaving journalists waiting outside the All Blacks hotel.
In her social media post, Malcolm said: "It's brutal when you lose and yes tough questions need to be asked".
"Ian Foster and Sam Cane have been bagged so much in the media, I felt they needed a little space to think. My bad? Hindsight? I'll take that hit. I am here to look after people as well as do comms."
On Sunday, as he boarded the team bus, Foster said he had "no idea" why the media briefing had been cancelled.
The media schedule for the Irish series had been confirmed weeks in advance with an 11.30am stand up the day after the final test match.
Malcolm was responding to an earlier LinkedIn post from former NZ Rugby communications manager Mike Jaspers in which he was critical of the way the All Blacks communications had been run.
"I feel for All Blacks coach Ian Foster, but really in the depths of a crisis the correct comms approach is not to duck the difficult questions unless you really are hanging up your boots," said Jaspers. "And I doubt he is.
Jaspers said the All Blacks coach "should have fronted and delivered the mea culpa, acknowledged the hurt, talked about letting down the jersey and the fans, the lessons to be learned, we've been through dark days before etc and his determination to right the ship".
"Fighting talk. Fronting up. That's what fans want to see and hear.
Commenting on Jasper's post, Malcolm said: "It was my decision not Ian Fosters not to front so I'll wear that. I was protecting people who have been subject to two weeks of hammering in the media. The media didn't want answers, they wanted a coach to step down. They also wanted insight and analysis 25 minutes after final whistle."
- With Otago Daily Times
