Lock Ryan was one of three injury concerns along with wingers Mack Hansen (calf) and James Lowe (eye) after the final pool game against Scotland at the weekend, which the Irish won to extend their winning streak to 17 games.
"James Ryan is seeing a specialist and we are hoping for better news than originally anticipated," Kearney said.
"Mark Hanson took a bang to his calf but is improving. Both him and James are making good strides.
"At this stage, no one is ruled out for the match against New Zealand on Saturday night."
Ireland have been playing tests against the All Blacks since 1905 but got their first victory in 2016 with four more wins following in the seven matches since that breakthrough victory in Chicago.
That tally included two wins to clinch last year's test series in New Zealand but it was the All Blacks who ran out comfortable 46-14 winners in the quarter-finals of the last World Cup in Japan.
Ireland have never been past the World Cup quarter-finals and hooker Ronan Kelleher was cautious when asked whether the aura of the All Blacks had been diminished over the last seven years.
"We know how good a team they are and how well they play at big tournaments," said Kelleher, who was still at school when Ireland beat New Zealand for the first time.
"I suppose that it is something you'd love to dream about, a spot on the big stage, and certainly probably the biggest game in my career so far. (But) for me personally, this needs to be treated like any other test match."
Ireland's first two wins over New Zealand, in Chicago and back in Dublin two years later, came during the reign of Joe Schmidt, who is now an All Blacks assistant coach under Ian Foster.
"It certainly adds another dimension to it," said Kearney, who remains close to Schmidt.
"He was an amazing coach for Ireland and took (us) to a new level.
"A lot of people are talking about Joe knowing players inside out but, to me, all teams know each other so well now that I don't necessarily think that's any great advantage."
