Ronnie O'Sullivan is "a very hot favourite" to retain his world title, according to practice partner and former world champion Peter Ebdon.
O'Sullivan has not played competitively since winning at the Crucible last May but Ebdon says the four-time world champion is in better form than ever.
"If anybody thinks he's not going to be ready for Sheffield, they are really badly mistaken," Ebdon told BBC Sport.
"He's playing at an unbelievable level and, if anything, he's improved."
Ebdon, world champion in 2002 and three times a Crucible finalist, has been practising with O'Sullivan at the Star Snooker Academy in Sheffield.
And Ebdon maintains O'Sullivan's edge has not been dulled by his 12-month sabbatical from the game.
"He's in top form and he will take some beating. I think you'll see Ronnie O'Sullivan playing better snooker than he played last year," said Ebdon.
"His safety game last year was absolutely phenomenal. He took safety to a completely new level; it was almost like an art form.
"He won the tournament with probably only 30-40% of his long game and probably nowhere near his break-building capability as well.
"But his all-round game is spot-on at the moment and it's going to take a world-class player playing absolutely out of his skin to compete with him, let alone beat him."
Shaun Murphy, world champion in 2005, said he expected O'Sullivan to be match sharp from the beginning of Saturday's opening match against qualifier Marcus Campbell.
"I would imagine that his preparation has been almost scientifically pinpointed to the last millisecond," Murphy said.
"I would think that when he gets to the Crucible, he'll be ready and that he will have left no stone unturned. I'm sure he will put on a good show."
World number one Mark Selby admitted O'Sullivan was still the one player all his rivals wanted to avoid.
"I am sure it will be difficult for him to turn up and play to what he is capable of after a year out," said Selby.
"But, at the same time, we all suspect that if anyone can turn up and win the World Championship in circumstances like that, then it is probably Ronnie.
"Everyone and anyone would try to avoid him because, when he is on his 'A' game, I don't think there is anyone out there who can beat him."
World number six Mark Allen said O'Sullivan's break from the game could work in his favour, especially given the demands of the revamped snooker tour.
"The person coming into the World Championship the freshest is probably Ronnie O'Sullivan because he hasn't played any snooker," said Allen.
"The game has gone forward in the last year, a lot of good players have won tournaments and the money is going up at the top end. It is progressing but maybe a little bit in the shadow of Ronnie.
"Stephen Hendry retired last year from the Crucible and he hasn't been mentioned this season. Hendry's the greatest player that's ever played the game, but it's about what the press want to write.
"Unfortunately, the sorry state of this game means that snooker needs Ronnie O'Sullivan.
"I said a few years ago that I didn't think snooker did. Now I think I'll have to change my mind because there's not the same buzz whenever Ronnie's not there; he's the only person in the game who can generate that atmosphere.
"That's no disrespect to the other top players, it's just what Ronnie brings. A bit of the unknown, a bit like Alex Higgins used to do.
"People used to come and watch Alex because they didn't know what they were going to get. One day they'd get the genius, another day he might head-butt someone. That's what people pay to see."
Ebdon, who will equal Steve Davis's mark of 22 consecutive appearances - second only to Stephen Hendry's record 27 - at the Crucible, added: "Ronnie's a genius, he operates on a different level to any other snooker player that's ever picked up a cue. He's that good that you'd pay to watch him in practice.
"Obviously, we'd love Ronnie to play in all the big events. He's loved and adored my millions of snooker fans around the world and for very good reason.
"Snooker does very well without him, but he does bring something to snooker that nobody else can bring to the game."