O'Sullivan withdraws threat to snub Masters
Ronnie O'Sullivan of England plays a shot in the final match of the World Snooker Championships at The Crucible in Sheffield, England, on May 6, 2013
O'Sullivan qualified for the London event with his latest World Championship title in May, but he initially appeared unsure whether to appear at Alexandra Palace from January 12.
Writing on Twitter on Friday, the 38-year-old said: "Thinking about entering the masters at ally pally - what ya think - yes or no - so unsure".
But a reply to that tweet came from World Snooker's official account and read "yes".
O'Sullivan then wrote around an hour after his original post: "Entered and done - let me entertain u ally pally".
O'Sullivan lost to Stuart Bingham on Thursday in the quarter-finals of the UK Championship.
And on Friday, several hours before his message regarding the Masters, he wrote on Twitter of the need to get away and indulge his passion for running.
He wrote: "need to run and run and run and get out of snooker halls and hotel rooms and breathe fresh air man - just need it bad".
Former world number one O'Sullivan has won the Masters four times in his 21-year professional career but has endured a fractious relationship with snooker in recent years.
The five-time world champion missed much of the 2012-13 season and expressed hope during the ongoing UK Championship that the switch from ranking points to a money list system would enable him to "play the system", take further breaks and preserve his world ranking.