Serena Williams has decided to end her 2005 season early, withdrawing from the final two tournaments due to left ankle and knee problems. Williams' last event was the China Open in mid-September. She's been bothered by the knee and ankle injuries for several months. "My doctors and trainers have advised me that my leg needs to fully recover in order for me to play at the level that I'm accustomed to playing," Williams said in a press release. "This has been such a disappointing year for me because I'm such a competitive person and I like to win for myself and for my fans. I tried my best to fight through my injuries during the season, but I now realize that I need to take some time off to rest my body and get back to being 100 percent healthy." Williams' last two tournaments were to have been the Swisscom Challenge in Zurich on October 17 and the Advanta Championships in Philadelphia on October 31. Currently ranked 11th by the WTA Tour, Williams captured the Australian Open this year and also reached the semifinals at the Dubai Duty Free Women's Open and the quarterfinals at the NASDAQ-100 Open in Miami and the Bausch & Lomb Championships in Amelia Island. Despite only one title in 2005, Williams still finished the year with $1,076,226 in prize money. "I'm really disappointed that I will not be able to finish out the year in Zurich and Philadelphia, which are great tournaments that always have a lot of top players in their fields," Williams added. "But I'm going to be busy these next several weeks rehabbing, training and getting healthy so that I can play my very best for myself, the fans, tournaments and sponsors in 2006." Williams' sister, Venus, decided to pull out of next week's Kremlin Cup, citing a knee injury.