It would be a massive blow to both Kirwan and the Blues if the 30-year-old, who has played 70 tests, left. Experienced All Blacks prop Tony Woodcock recently announced his decision to move to play under Jamie Joseph at the Highlanders, and Kirwan was too late with a bid for prop Ben Franks, who has chosen the Hurricanes after leaving the Crusaders.
Nonu's probable departure would leave Kirwan with only Francis Saili and Michael Hobbs in the midfield.
Nonu remained careful with his words when reflecting on a difficult season at the Blues in which the team won only four games and coach Pat Lam lost his job.
"It was a learning experience ... ," he said. Asked if the regular defeats hurt, he replied: "It does, that's why we play the game. To win."
As for his relationship with Joseph, who has contacted Nonu about a move, the player said: "I've known Jamie for a long time. He coached me at the Lions. He's a top man and great coach. He's done wonders at the Highlanders. It's about finally deciding what I want to do."
Loose forward Adam Thomson is another All Black likely to be moving on, probably overseas because of a lack of game time with the national team.
When All Blacks coach Steve Hansen was asked yesterday if he would select the pair for the end-of-year tour to Europe if they announce they are moving overseas, he said: "We'll just have to see about that."
Nonu was a little downbeat when assessing the All Blacks' recent performances before tomorrow's Rugby Championship test against Argentina at La Plata. He said it was hard to win with an expectant New Zealand public at times.
"They (expectations) are always high but it's ironic because we play a side and maybe we pile on the points and people say: 'no, the opposition needs to get better', and we play a test match where we don't actually pile on the points and they say: 'well, you're not meeting our expectations'. People tend to forget it's a test match.
"That's the reality of playing rugby in New Zealand, but if you think about playing in Dunedin (when we beat the Springboks a fortnight ago) that's a real test match.
"We haven't really quite got going as a backline. It's hard to try to make things happen when everyone expects so much from our team.
"I think we just have to improve 5 to 10 per cent each, really."
Patrick McKendry flew to Argentina courtesy of LAN Airlines.