The absence of the five-times world champion and snooker's biggest draw - who won the sport's second biggest event in 1993, 1997, 2001 and 2007 - would be a huge blow to tournament sponsors Coral and snooker fans.
O'Sullivan is a strong favourite to win the event, but admitted he might have to play on one leg in his first-round match against Daniel Wells of Wales on Thursday.
"I might have to pull out the UK," said O'Sullivan. "I've just twisted my ankle. I'm gutted."
O'Sullivan is an avid runner, and has suffered several injuries over the past year because of his daily training schedule.
In his latest Eurosport blog, O'Sullivan admits he is relishing the chance to win a fifth UK title that would see him draw level alongside Stephen Hendry and leave him one adrift of Steve Davis' haul of six UKs.
"I've had some magical moments at the UK, the greatest of which is probably winning my first ranking event against one of my heroes in Stephen Hendry," he said.
"I've been lucky enough to win this event on four occasions. It is an event I love playing in, second only to the World Championship."
The next episode of the Ronnie O’Sullivan show airs this Saturday at 12.30pm on British Eurosport 2 HD.
The UK Championships are LIVE on British Eurosport 2 HD from 1pm on Saturday.