Along with Allister Hogg and Chris Paterson from Edinburgh, and Moffat">Stuart Moffat and Paul Thomson from the Borders, JP and Bevvy will sit on the committee of the new body which has appointed Jim Hay as its first chief executive.
JP told The Scotsman: "This has been overdue. All the other major countries in the world have a players' association and I think it's important from a players perspective, not just as a voice in a conflict with the SRU - although that is obviously a part of it - but the main thing is players' welfare: financial, legal representation and many others aspects.
"It can only be of benefit to rugby, to the players and the SRU, because we're looking to build a good relationship with everyone employed at Murrayfield as well. It won't work if we don't move forward hand-in-hand.
"It would be nice to have had the SRU's support before now, but Jim will sit down next week and discuss it further with Fred McLeod, and we hope the funding will come from that. We had to get moving and launch it now because we don't want things to drag out at this stage of the season."
Although the organisation has no official status, SRU director of corporate affairs Mike Keohane said: "As I understand it, many of the professional players have said they will join. We will have to see how it develops, but obviously we would want to work with the organisation."
It is expected that Hay will represent the players on the new Scottish Rugby Council, which takes power next month with Gavin Hastings yesterday joining Finlay Calder and Andy Irvine among those being put forward as council members.