The WRU have offered six international stars central contracts, to counter the four regional sides' threat of defecting to a new Anglo-Welsh league.
The regions are refusing to sign a new participation agreement for next term, to continue under WRU control.
The WRU is understood to be considering loaning six top stars, including Cardiff's Wales and British Lions captain Sam Warburton, to frontline clubs in England.
Welsh bosses have even mooted setting up new regional outfits to compete in the RaboDirect Pro12 should the Scarlets, Blues, Dragons and Ospreys withdraw from the Celtic League.
The WRU would be prepared to keep their top internationals fresh for Test rugby through loans at Premiership clubs, while their new franchises developed.
Winstanley has been quick to shrug off the scheme though.
When asked if Premiership Rugby could countenance the WRU plan, Winstanley told Press Association Sport: "Probably not no.
"I hadn't heard about that, but if they were to do that, then I wouldn't have thought that that would be something we would support.
"I can't comment specifically on what the WRU are planning, but whether or not we see it fit to effectively take those players on loan, I would think it highly unlikely."
Wales centre Scott Williams, meanwhile, is prepared to sign a new Scarlets contract, provided the WRU and the regions can resolve their civil war.
Coach Simon Easterby has confirmed the Scarlets have offered both 23-year-old Williams and fly-half Rhys Priestland new deals.
Williams' Scarlets offer has been countered by the WRU's move for central contracts, leaving the centre admitting he is stuck in limbo.
"It is a frustrating time for us players with everything that's going on," Williams told the Western Mail.
"Nobody is really sure what's happening.
"I am just keeping talking to the Scarlets, keeping close to them, that is where we are at the moment.
"The ideal scenario would be for the WRU and regions to sort something out and for me to stay."
- Sports & Recreation