Alex de Minaur has joined the chorus of tennis voices calling for the crowded men's tennis schedule to be shortened, warning that players are in danger of having their careers ended early with physical and mental burn-out.

His lament came on the day when he cited his own mental fatigue during his surprise exit at Roland Garros to Alexander Bublik on Thursday, and while his Australian colleague Adam Walton was having to battle with a shoulder injury in his loss to Andrey Rublev.

De Minaur then chose the moment to launched a wider broadside about the state of the men's ATP tour program, echoing the complaints kicked off by his Sydney colleague Jordan Thompson earlier in the week.

"No-one's got a solution," said de Minaur, admitting the tour grind was affecting him after his 2-6 2-6 6-4 6-3 6-2 loss.

"But the solution is simple: you shorten the schedule, right?

"What's not normal is that for the last three, four years I've had two days off after the Davis Cup and I've gone straight into pre-season, straight into the new season again," said de Minaur of the gruelling program that kicked off with the United Cup in December, 33 days after the Davis Cup Finals ended.

"Once you start, you don't finish until November 24. So it's never-ending. The way it's structured ... I had to deal with that. I'm still dealing with that right now.

"The solution is you shorten, because what's going to happen is players' careers are going to get shorter and shorter because they're just going to burn out mentally. There's just too much tennis."

Thompson, who has been battling on all season with three injuries which he believes have only been exacerbated by the ceaseless tour grind, had earlier described the ATP schedule as "shit" and "just a joke".

Two-time French Open finalist Casper Ruud also picked up the theme after his own injury-hampered defeat to Nuno Borges on Wednesday as he likened the ATP's ranking system to a "rat race" with players feeling compelled to compete in the men's tour's mandatory events even if they are carrying injuries.

"You feel you're obligated to play with certain rules that the ATP have set up with the mandatory events. You feel like you lose a lot if you don't show up and play ... the punishments are quite hard, in terms of everyone else will play, gain points, and you won't.

"If you don't play a mandatory event, they cut 25 per cent of your year-end bonus.

"You're forcing players to show up injured or sick, or whatever, when that's not what I think is very fair."

Brisbane's Walton admitted after his straight-sets defeat that he was still battling on with an arm injury "that's not great".

"The season's pretty relentless. I don't have the luxury, like some of the top players, in being able to play less. I guess if you're good enough, you don't have to play as much to collect points, right?" said the world No.91.

"So in order for me to collect all the points, I've got to play a lot. I don't have a solution, but yes, it is very taxing on the body."