The organisers said that the world No 16 informed them of his decision yesterday, two days before the event was due to tee off at the Arnold Palmer-designed Orchard Golf and Country Club.
Their spokeswoman said: "Woosnam was told by his doctor to take three months off because of back trouble."
Despite his absence, the tournament still boasts an impressive field led by the world No 1, Nick Price of Zimbabwe, and the second-ranked Greg Norman. Also competing is the defending champion, Bernhard Langer, ranked fourth in the world.
The 72-hole tournament will, for a week at least, make the Philippines the focus of the golfing world on the second leg of the Volvo PGA European Tour.Reuse content