Tiger Woods has fallen out of the world top 20 for the first time since January 1997.The former world No.1 has not played since May 12 because of knee and Achilles tendon injuries although he is expected to announce later this week that he will return to action at the WGC-Bridgestone Invitational on Thursday week.That would test his fitness ahead of the year's final Major, the USPGA Championship in Atlanta, which starts on August 11.Woods has dropped from eighth to 21st in the rankings in that time and last Wednesday announced on his website that he had fired his longtime caddie, New Zealander Steve Williams.World top 201. Luke Donald (ENG) 9.72pts2. Lee Westwood (ENG) 8.333. Martin Kaymer (GER) 7.264. Rory McIlroy (NIR) 7.065. Steve Stricker (USA) 6.946. Phil Mickelson (USA) 6.277. Dustin Johnson (USA) 5.758. Jason Day (AUS) 5.449. Matt Kuchar (USA) 5.3810. Nick Watney (USA) 5.2411. Charl Schwartzel (RSA) 5.2112. Graeme McDowell (NIR) 5.2013. Bubba Watson (USA) 4.7714. KJ Choi (KOR) 4.7115. Paul Casey (ENG) 4.6216. Ian Poulter (ENG) 4.4517. Adam Scott (AUS) 4.0518. Hunter Mahan (USA) 3.7819. Robert Karlsson (SWE) 3.7520. Retief Goosen (RSA) 3.67