Corey Parker has voiced serious concerns about the NRL's post-Origin player workload, warning that the tight turnaround between rep duty and club games is placing elite players under undue strain.

With 34 players taking part in Game II in Perth and only four of them sitting out Round 16, the squeeze on the remaining 30 is drawing attention from those who know the toll first-hand.

Speaking on SEN, Parker questioned whether enough has changed in how the game manages the brutal Origin-to-club cycle, suggesting players are being pushed harder than in previous eras.

"When I was playing, it was a badge of honour, you wanted to do it," he said.

โ€œThere wasn't 27 rounds in the competition, so the games were less. There [weren't] pre-season comps."

He suggested that the modern game carries additional demands with extended pre-seasons, rep fixtures and relentless scheduling.

The Roosters versus Cowboys clash looms as a flashpoint for the debate, with nine players from both sides expected to back up just days after Origin.

"It's a must-win for those teams because the Roosters are sitting in 8th spot, Cowboys sitting in 10th," Parker said.

"Out of those two teams, nine players that played over there in Perth have to back up, they don't have to, but they [feel] obliged to back up."

Penrith opted to rest all five of its Origin players for the trip to Auckland, yet ended up jagging the most unlikely of upsets over the red-hot Warriors.

But with many players still suiting up, the league faces a delicate balance between delivering competitive club games and protecting its marquee players.

"You can say that there's a few more extra days, but it is still the mental drain, the physical drain of backing up," Parker said.

The risk of fatigue-related injuries remains a live issue, with Parker raising the hypothetical of multiple star players breaking down in one round.

"Let's say, all the players backed up and you have strains, hamstrings, injuries to say five of the real key players for either side. Well then, there is a massive concern for the game."