text: Following the announcement of the new global calendar in March, Premiership Rugby confirmed the 2019-20 domestic season will start in early September and finish at the end of June.
  Leicester's Tom Youngs had said the proposal "fills players with dread".
  The RPA has now said a shortened two-month off-season will be "seriously detrimental to player welfare".
  Premiership Rugby has previously said the 10-month campaign will allow clubs to become "more sophisticated" in their management of players, with chief executive Mark McCafferty insisting player welfare remains the priority.
  But an RPA statement on Monday read: "The Premiership season is already longer than comparable contact sports, including Super League, NFL and AFL.
  "Extending an already arduous season from nine months to 10 has serious implications for players, given the potential increase to the game, training and psychological loads they face.
  "The physical and mental strain placed on participants of professional contact sport cannot be underestimated."
  England, Wales, Scotland and Ireland will all be playing international matches in June this summer, while the British and Irish Lions are also touring New Zealand.
  The RPA has concerns that an extended season could overwork any players involved in future international summer tours - a worry shared by Tigers captain Youngs.
  "Perhaps most worryingly is the incredible strain these proposals would place on international players," the statement continued.
  "If the Premiership season retains its current start date, the addition of a July tour schedule will lead to an 11-month season for these players.
  "This cannot be avoided unless these players start their domestic season later, which brings into question the need for the season extension."
target: The Rugby Players' Association has "unanimously rejected" proposals for an extended 10-month Premiership season.