Ronnie O'Sullivan says allowing spectators into the Crucible Theatre for the World Championship is treating snooker players like "lab rats".
The tournament, which begins on Friday, will be the first indoor sporting event with crowds, allowing around 300 supporters to attend each session.
Qualifier Anthony Hamilton, who suffers from severe asthma, says it is "ridiculous" and "too early" for fans.
Five-time world champion O'Sullivan said players "all run a bit of a risk".
A number of sports have already returned behind closed doors but snooker will be the second government-backed pilot event after the Surrey v Middlesex friendly in cricket to be staged in front of fans.
Those that have booked tickets to attend the Sheffield venue will be placed in 'bubbles' of up to four people - limited to a maximum of two households - and will be socially distanced from others in the arena.
Temperature checks will not be in place and although face masks must be worn around the venue they can be removed once spectators are seated inside.
World number 48 Hamilton pulled out of the Tour Championship - the first event that was played on the sport's return - because of health concerns and called the decision to allow people to take off their masks in the auditorium "a mad thing".
He added: "Let's say one person gets ill and dies from the Crucible, that is one person who has died for no reason, just for entertainment.
"I won't be comfortable in there personally. I don't know why anybody would be comfortable - we all know it is airborne."
Hamilton has reached the World Championship quarter-finals four timesThe World Snooker Tour said having the championship designated as the first indoor event in the UK with fans attending since the start of the pandemic was a "fantastic triumph" and that health and safety was the "highest priority and protection for our fans, players and staff".
And Shaun Murphy, who won at the Crucible in 2005 said: "We're all desperate to get crowds back in - they bring that X-Factor to an event.
"I get Ronnie saying fans are an unnecessary risk. I understand where these concerns come from and I'm sure it will be a case that the person who coughs first or sneezes first might get the daggers from everyone, but that's become the new normal.
"We need to take on new measures but that doesn't mean we can't ever leave the house again.
"I think we just have to go right guys, we really want to get back to where we were but we've got to get back there slowly. The other option is to never go to a live sporting event again, stay inside, don't come out.
"I get their fears and I understand it but it's a pilot at the end of the day and we've got to move on."
However, O'Sullivan said: "I defy anybody if they have been keeping their distance from people for four months to say, oh right, now you've got to go into a room full of people - unless you have got a death wish, and some people have in many ways and they just don't care.
"But if you are one of these people that happens to care about your health and are taking it seriously, I totally get how [Hamilton] feels.
"I would feel a bit strange walking in a room with 10 people I don't know, and I have done. I didn't feel comfortable.
"So I totally respect where Anthony is coming from, and where other people are coming from - they want crowds in there, they want things back to normal. We have a choice - we don't have to go and play. We all run a bit of a risk.
"I have the option not to play but I've decided to play. Maybe with 5,000 fans I could see it's a bit of an income you're going to lose, but 200 fans, is it really?
"Maybe they have to start doing a test on crowds at some point and I've heard people say they're treating the snooker event a little bit like lab rats - you've got to start somewhere, start with snooker players.
"Less insurance to pay out for Anthony Hamilton than there is for Lewis Hamilton."
O'Sullivan says he has had friends die from Covid-19 and has not been within 20 feet of his mother, who is in the 'high risk' category because she had pneumonia last year.
"It's not until you've had people close to you that have gone through it, and know someone who has died," he said.
"I don't think it has been taken seriously enough."
The opening matches begin at 10:00 BST live across the BBC, with defending champion Judd Trump in action against Tom Ford, while O'Sullivan starts his campaign against Thailand's Thepchaiya Un-Nooh on Sunday.
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