World number one Tiger Woods had everybody guessing today when he did not turn up for his planned practice round at Sawgrass on the eve of the Players Championship, the biggest event of the golf season so far.

A scheduled press conference was cancelled after officials were informed that Woods was not going to be at the course.

Inevitably, there was speculation that the 30-year-old's absence may have something to do with his health of his father Earl, who has been battling cancer.

Chris DiMarco, meanwhile, was forced to withdraw from the tournament after injuring a rib muscle.

DiMarco, the world number 11, sustained the injury while on holiday with his family in Colorado over the weekend. The injury worsened when he practised at his home course in Orlando, Florida on Sunday, forcing his withdrawal from the tournament unofficially dubbed the fifth major.

DiMarco, who won the European Tour's inaugural Abu Dhabi Golf Championship in January, has been replaced by PGA Tour rookie Camilo Villegas of Colombia.

Villegas is scheduled to tee off in tomorrow's opening round with Nick Faldo and Rory Sabbatini.