Vunipola learned on Sunday he will be out for four months after injuring a knee during Sarries' defeat of Sale.
The 24-year-old had only recently returned after a year blighted by knee and shoulder problems, the latter forcing him out of the Lions tour.
Speaking prior to his latest setback, he said "something has to change".
"I didn't enjoy being on the surgery table twice in one year and that's supposed to be deemed as normal," he told BBC Radio 5 live's Rugby Union Weekly podcast.
"Kids want to play rugby because it's fun, but they also need to know that it's tough, and it's normal to have surgery at 25 because you're so worn down.
"I'm not complaining, I just want people to understand that having surgery is not fun, and it's not fun being injured.
"It gets to a point when you are just done, and you can't control when your knee goes out or your shoulder comes out.
"That was the weirdest feeling I've ever had in my life, not being able to control that and prevent it from happening.
"So something probably needs to change, or the players will just burn out."
Asked if he would consider a pay cut in return for playing fewer games, Vunipola replied: "Yes."
England's elite players are limited to 32 games per season, but Vunipola says recovering from a match can take up to five days.
"32 games is a lot, but it's doable," he added.
"But do you want people to just do it, or do you want people to go out there and smash it?"
Vunipola is one of a number of leading players to voice their opposition to the proposed extended season post-2019, with the Rugby Players' Association not ruling out strike action.
'Missing the Lions made me grateful'
Vunipola was expected to play a leading role for the Lions in New Zealand, but pulled out of the tour because of an ongoing shoulder problem.
He says missing the tour has given him a fresh perspective.
"I never [used to be] grateful for being on these tours. I kind of took it for granted. [Missing the Lions] made me be grateful for going on these tours.
"When I was on holiday, all I wanted to do was be on tour. So now, if ever I'm on tour, I'll never sit there and be negative."
'I'm learning my limits with alcohol'
Vunipola revealed he only started drinking alcohol last year, and is still learning how to deal with it.
"After I did my knee against Argentina, and went through a tough break-up with my ex, I needed something to take my mind off it," he said. "So I drank that night at [England's team hotel] Pennyhill for the first time ever.
"I just never got into it before, and it took a massive change in my life to bring it on. I was always adamant I was never going to drink.
"I'm still learning [my limits], but it's something I do with the boys."
I'd like to be a plumber or electrician'
Vunipola says he does not fear life after rugby, and says he would like to train as a plumber or electrician upon retirement.
"It's something I think will be the closest environment to a rugby environment," he said.
"Life after rugby will come. A lot of people are scared of it, but my philosophy after rugby is 'just try'."
Tongan first, English second
Vunipola, who moved to the United Kingdom with his family at the age of six, says he still considers himself Tongan first and foremost.
"Both my parents are Tongan, my culture was fully invested in Tonga," he said.
"I'm here now, and I obviously embrace it, but I'm not going to sit here and say I'm born and bred English, because I'm not.
"But I'm very proud to represent us as a country, I have adopted the English culture, and I'd like people to see me as one of their own."