England captain Dylan Hartley insists that the extended club season being proposed by Premiership Rugby is "not welcome" among players.
The umbrella organisation for the 12 Aviva Premiership clubs is seeking to establish a structure that lasts 10 months running from September to June as part of negotiations for the new global calendar, which is to take effect from August 2020.
With summer tours moved to July it means that internationals will face an 11-month season, prompting England stars Billy Vunipola, Ben Youngs and Joe Marler to declare that they regard strike action as a viable option if their voices are not heard.
Hartley, the most senior player to have spoken on the issue, insists opposition to the proposal is the consensus view.
"I can't obviously speak for every player, but the general feeling is that an extended season is not welcome," Hartley said.
"Player welfare is paramount, both mental and physical. I don't know the answers, but I can see both sides.
"The season is relentless and there is always another big game around the corner. When you lose, you've got to move on pretty sharpish.
"The games come thick and fast and if you're an international player your focus shifts to that, then back to your club again. So the mental side of player welfare is so important."
Hartley's thoughts have been echoed by England team-mate Joe Launchbury, who fears that international players will not be sufficiently rested if August is the only month of the year absent of rugby.
"Every week is a massive game. To try to expand that and make the season longer with less rest period is hard to see from the players' points of view," Wasps captain Launchbury said.
"You need that mental break and that's almost as important as having a physical break. You need that five week rest that the Rugby Players' Association fought extremely hard for the players to have."