Wayne Smith, the All Black assistant coach whose brain is one of the most sought after in rugby, has admitted to concern over his long-term health after a number of concussions during his playing days.

Smith, 58, who last week signed on as Steve Hansen's assistant coach for the next two years, was a 71kg first-five during his All Black playing days in the 1980s.

"I have a personal concern not [just] for my own welfare but the mates I played with," Smith tells NewstalkZB's Tony Veitch in an extended interview today.


"I would have 'woken up' in the changing rooms three times in my career and probably had another three reasonably major head knocks, and in those days you played the next week.

"The thing that strikes about that was I never played well the next week. Never. There was something inside you telling you that you weren't right ... from that perspective I'm reasonably concerned [about the future]."

Smith, who played 17 tests for the All Blacks, said players in his day did not have the same access to information that modern players did, but that did not necessarily lessen the risk.

"If you look at today the impact is higher and the concussions, where this is more information about them, they also seem to be worse. It's a major challenge for World Rugby and something we're really trying to change."