|Betfred World Snooker Championship|
|Venue: Crucible Theatre, Sheffield Dates: 20 April-6 May|
|Coverage: Watch live on BBC One, BBC Two, Red Button, iPlayer, Connected TV, BBC Sport website and BBC Sport app.|
Former world champion Ken Doherty has accused Ronnie O'Sullivan of playing with disrespect during his opening-round defeat by amateur James Cahill.
Doherty, who won the title in 1997, also said the world number one did not look well during the 10-8 loss.
"He played very casually, it was almost with a lot of disrespect in a way," BBC pundit Doherty said about Monday's first session which Cahill led 5-4.
"He didn't want to be there, didn't look like he fancied the job."
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Five-times world champion O'Sullivan, 43, missed several simple pots and often looked dejected in his chair as debutant Cahill pulled off one of the biggest shocks in Crucible history.
"The most important thing for Ronnie and for snooker is that he's healthy," Doherty added.
"He doesn't look well, didn't play to his best. The game is tough when you're not feeling good."
After the match, O'Sullivan said his "limbs felt heavy" and he "had no energy".
'We think Ronnie is super human'
Six-times world champion Steve Davis was also critical of O'Sullivan's demeanour during the first nine frames.
"For Ronnie O'Sullivan, that first session was a tough one," Davis said.
"He looked yesterday like he didn't want to be there and I don't know the reasons for that, but he played like he didn't want to be there.
"He was bailing out in some shots just by attacking all the time. He's an attacking player but when you are attacking so much it almost goes the opposite way. It's sort of like you're hoping to be knocked out, in a strange way."
"We always think Ronnie O'Sullivan is super human and doesn't suffer with nerves, but if you are going to suffer with nerves the Crucible is where it is going to happen. The enormity of the World Championships weighs heavy on him."