Jamie Roberts has become the latest player to publicly oppose Aviva Premiership's plan to introduce a 10-month club season.
Negotiations for the new global calendar, which takes effect from 2020, have seen England's top flight propose a schedule that would take place from September to June with international tours staged in July, leaving August as the only rugby-free month.
Roberts, the Wales centre who is studying for a Masters degree in medical science part time while playing for Harlequins, believes the length of the proposed season would have a substantial impact on welfare.
"The Rugby Players' Association stance is pretty clear - rest is equally as important as playing," Roberts said.
"The lads will tell you that when you have a good off season and rest and get a good pre-season in, that's when your body feels at its best.
"If you are going to extend the season you have to remember that international players will be playing into July.
"You can't expect them to have four weeks off and maybe three weeks pre-season. It is crazy.
"In-season breaks aren't the same because you will still be in training. That mental time away from the game is equally as important."
The first five rounds of the Premiership season have been notable for the number of injuries sustained by numerous clubs, with Quins themselves entering Saturday's defeat at Northampton without 25 players.
Among the explanations offered for the full treatment rooms are the law tweaks to the tackle and ruck that are currently being trialled.
"The ball in play time is higher. The collisions are tough, everyone can see there's been quite a few injuries. The physio room has resembled a bit of a morgue at times," Roberts said.
"One thing I have noticed is defences during first, second and third phases are not competing for the ball.
"They are just making that tackle and filling the field so there's not too much space out there to try and exploit.
"And that means there's a lot of two-man collisions, you're getting halted by a couple of blokes rather than one.
"Whether that has an influence on the injury rate, I don't know, it's hard to quantify. The game has always been attritional, it's never been too different and we carry on."