Seven-time champion Stephen Hendry believes the World Championship would be a "poorer event" without Ronnie O'Sullivan.
And Hendry thinks the five-time champion is not fully focused.
"Personally I think it is a sign he has got other things on his mind," he said.
"He is not focused properly on winning the World Championship."
But the Scot added: "The tournament and snooker would be poorer without him."
"O'Sullivan is a dominating feature in snooker whether her wins or not, he is a superstar and people recognise him not just for playing snooker."
In 1996 he was charged with bringing the game into disrepute after playing left-handed against Alain Robidoux, who accused his opponent of disrespecting him. The charges were later dropped.
At the same tournament he was found guilty and fined for assaulting a media official, while in 2013 he was warned by the referee for making an improper gesture during his semi-final against Judd Trump.
In a wide ranging interview with BBC Sport Hendry also had his say on whether the World Championship should leave Sheffield, growing the game globally and the importance of China.
'It's our Wimbledon'
Hendry insists the World Championships should never leave the Crucible, despite calls for it to move from Sheffield.
He said: "It is like our Wimbledon, it would not be the same if we did not play at the Crucible.
"People have the ability to watch it all over the world and wherever I have been they always talk about the Crucible, I think it is known well enough.
"It is the pinnacle of our sport and I think if you asked players if they would rather win an Olympics or this tournament they would want to be world champion at the Crucible."
'China's thirst for cue sports is phenomenal'
Hendry says China is an important market for the game but is surprised no one has emulated China's most successful player and world number three Ding Junhui.
He said: "There are so many people playing in China and in the academies there, so it is strange that no one has come through to be as good as Ding.
"China demands so many events, they have a thirst to watch events and watch Ding and I think they have their eyes on taking the championship to China one day.
"They like the dedication involved with snooker, they like that it is a gentleman's sport and admire the way the players go around the table and sit with bow ties.
"Their thirst for cue sports is phenomenal."
'Judd to dominate for 10 years'
Hendry thinks there will eventually be a Chinese world champion but not while England's Judd Trump is playing.
He added: "I thought Ding would have won it by now but you could be looking at 10 years before anyone from China wins it. You look at Trump - the age he is, he will dominate for 10 years. If someone else came along they would have to be pretty special."