The 37-year-old Vickerman died at his family home in Sydney at the weekend.
RNZ reports there were no suspicious circumstances.
The players' association said it was trying to make sure players saw themselves as people first and rugby players second.
An NZRPA survey in 2009 found a third of players were unprepared and struggled during the first three months of retirement - while more than half took six months or longer to feel in control of their lives.
A reason for that, Mr Nichol said, was because a player's identity could be solely linked to sport.
