Tiger Woods is out of the world's top 20 for the first time since 1997.
The American golfer has not been able to play since May of this year because of knee and Achilles tendon injuries.
Woods has dropped from eighth to 21st in the rankings during the period, although he is expected to return to action at the WGC-Bridgestone Invitational next month.
The 35-year-old announced last week that he had parted company with caddie Steve Williams.