Defending champion Ronnie O'Sullivan (49) has withdrawn from The Masters at Alexandra Palace on medical grounds.
O'Sullivan was gearing up to claim a record-extending ninth Masters title.
'The Rocket' was scheduled to face John Higgins in the first round of the tournament this weekend at Alexandra Palace in London.
As The Masters invites the world's top 16 players, O'Sullivan's place will be taken by Australian Neil Robertson.
O'Sullivan was in action as recently as this week, playing four matches on Wednesday in the Champions League.
The Englishman lost three of those and subsequently pulled out of the tournament before his final group game.
'The Rocket' was visibly disappointed by his performances and even struck the table with his cue during a clash with Robert Milkins.