Mark Allen has asked the first questions of Ronnie O'Sullivan's withdrawal from World Snooker's new flagship tournament in China.

The International Championship in Chengdu, which offers world ranking points on a par with the UK Championship and a first prize of £125,000, gets under way tomorrow.

O'Sullivan yesterday withdrew on medical grounds, prompting World Professional Billiards and Snooker Association chairman Jason Ferguson to say it would mean "huge disappointment" for the Chinese supporters.

Northern Irishman Allen, among the likely title contenders after overcoming a passport blunder to travel out, wrote on Facebook: "So ronnie pulls out of china again!! Thoughts?"

The 26-year-old added in a later post: "Don't understand why he enters though. If he doesn't wanna play don't enter. It affects draws, rankings, sponsors, seedings and all."

O'Sullivan's condition was not disclosed - he was able to play an exhibition match against Jimmy White in Liverpool on Thursday.

Last year he suffered badly with glandular fever and pulled out of the Haikou World Open in China and the PTC finals in Ireland.

The Chigwell man has expressed a dislike for the heavy schedule and travel demands on players in the game, with the ranking system in its present guise placing an emphasis on the importance of players turning out each week.

Despite winning the German Masters and World Championship this year, by taking a four-month break from competition following his Crucible triumph O'Sullivan has drifted out of the world's top 16 players.

His ranking - currently 17th - will continue to slide for not travelling to China.

While the 36-year-old recovers at home, Allen will be looking to claim his second major ranking title, having won his first also in China at the Haikou Open earlier this year.

That came after Allen, on arrival in Haikou, launched a fierce attack on the tournament and local people which saw him reprimanded by World Snooker.

He almost missed the trip this time, having taken his wrong passport initially, leaving behind his visa.

But Allen is a player full of confidence and form, having recently won a minor tournament in Belgium by defeating world number one Mark Selby in the final.

"That win has been a long time coming," Allen said.

"I was really struggling earlier in this season, but I've spent a lot of time with my coach Terry Griffiths up at South West Snooker Academy.

"He's helped me get my mind right. And I've practised hard leading into this event. I had a good attitude throughout.

"I'm really pleased to be playing well again. We've got some very big tournaments coming up, the International in China next week and the UK Championship is not far away."

A dark horse for the eight-day Chengdu tournament is Stuart Bingham, who enjoyed 6-0 wins over both Selby and Neil Robertson in the Premier League in Guildford on Thursday, firing in four century breaks.

He and fiancee Michelle are due to marry next year, and Bingham's £16,000 one-night winnings will cover the cost.

"We're getting married in Cyprus in May so that pays for everything," Bingham said.

"In practice everyone can play like that but to do it on the main stage was unbelievable.

"I've beaten the world number one and former world champion - well I hammered them."

Absent from China along with O'Sullivan will be Stephen Lee. The world number seven has been suspended pending the outcome of an investigation by the WPBSA into betting matters.

Tomorrow's action in Chengdu sees former world champions Shaun Murphy, Robertson and Ken Doherty all start their campaigns.