World number two Rafael Nadal plans to take several weeks off after the Australian Open to properly recover from a nagging shoulder injury.
Nadal suffered the injury before the ATP World Tour Finals in November and said he was still "not 100 percent".
He said: "I had a problem before London with my shoulder and I had to stop for about 10 days before the (ATP) finals."
The 25-year-old Spaniard added: "It felt better again but resurfaced, I couldn't practice."
The Spaniard only decided on Monday to defend his title at the World Tennis Championship - a two-day exhibition tournament in Abu Dhabi.
Nadal will play the winner of a match between Jo-Wilfried Tsonga and David Ferrer in the semi-finals on Friday.
He is hopeful his shoulder will hold up enough for him to win both the Abu Dhabi tournament for a third successive year, and next week's Qatar Open in Doha.
The Australian Open gets under way on 16 January, and Nadal says he wants to use February to rest and practice.