England's top clubs will be allowed to spend about £250,000 more from next year to increase their squad depth in an attempt to prevent player burn-out.
Many of England's beaten side will be in action this weekend
Premier Rugby chief executive Howard Thomas told the Guardian newspaper he wants each Zurich Premiership side to have more than 40 players.
"We recognise that the size of squads needs to be larger," said Thomas.
"A study has been commissioned into burn-out and the welfare of players has to be of paramount importance."
The current salary cap restricts clubs to spending £1,997,000 on players per year.
The workload of leading players has come under extra scrutiny after England suffered their eighth defeat in 11 Tests against France on Sunday.
Many of that England squad will play for their clubs this weekend, while players from Wales and Ireland take time off.
Former England hooker and leading RFU official Fran Cotton called for central contracts for top players
He also wants administrators to take greater care to ensure an agreed maximum number of games played is adhered to.
Cotton told the Daily Mail: "My view is that you have to centrally manage the very top 30 players and to make sure that when we say there is a 32-game limit, then we mean 32."