They are believed to be the players at the top of coach Jamie Joseph's wanted list for the 2012 season.
Hurricanes captain Andrew Hore, whose home is in the Maniototo, is also thought to be a potential target, but his elite status might prove too difficult for the Highlanders' budget to cover.
In a further boost for the revived Highlanders, the Otago Daily Times can reveal exciting winger Kade Poki is keen to stay with the team instead of taking up a contract in Japan.
Neither Joseph nor agent Warren Alcock, who deals with both Gear and Nonu, could be contacted for comment yesterday.
Highlanders general manager Roger Clark said the franchise was not presently in contract negotiations with any player outside the region.
He did not discount the possibility of pushing for the signatures of the All Black backline pair but said the Highlanders were not talking to either player "at this stage".
"We're talking to a number of players and their managers," Clark said yesterday.
"But there's talking and then there's talking. We've talked to and talked about a lot of players over the last six months.
"Those names [Gear and Nonu] have been mentioned at different times but there aren't any serious discussions going on with either of those players or anyone like them."
Clark said the Highlanders, like the other four franchises, were constantly monitoring the market and seeing which players might be a good fit with the team.
"We talk about all sorts of people. You read that a player is looking at his options and you think, `I wonder if he'd like to play down here?' But that's all."
Once, the idea of the Highlanders recruiting stars like Nonu or Gear might have seemed fanciful.
But the franchise's dramatic improvement, the Hurricanes' struggles and Joseph's close ties to the Wellington-based players, especially Gear, add some weight to the speculation.
The Highlanders have already performed well this season, winning eight of their 12 games despite widely being expected to struggle.
But they would welcome more backline punch to complement outstanding fullback Ben Smith, injured-but-proven first five Colin Slade and All Black halfback Jimmy Cowan.
Gear would be an exciting and automatic selection on one wing, while Nonu would add firepower to the midfield.
The Highlanders have been well served at hooker in recent years by the indefatigable Jason Rutledge.
But if Hore was keen to come home - and if his signature wouldn't break the bank - the Highlanders would have to be keen.
Clark confirmed Poki, a revelation after being added to the squad as an injury replacement, was "definitely considering" staying with the Highlanders.
The Highlanders already have Smith, Slade, Cowan, Shaun Treeby, Josh Bekhuis, Adam Thomson, Tom Donnelly, Jarrad Hoeata, Nasi Manu, Aaron Smith, Lima Sopoaga, Robbie Robinson, John Hardie, Telusa Veainu, Kurt Baker, Nick Crosswell and Elliot Dixon signed up for next year.
Add an All Black or three to the mix and the future looks exceptionally bright.
"Our goal is to keep the nucleus of our players together. In some cases, we're locking them in for 2013 as well," Clark said.
"Then we'll see what's out there."
Clark hopes to announce three more signatures from the existing squad next week. The biggest names yet to commit include Rutledge, captain Jamie Mackintosh, prop Chris King and centre Kendrick Lynn.
