Friday October 3, 2008PARIS: Former world number one Maria Sharapova has pulled out of the season-ending WTA Tour Championships in Qatar as she has yet to regain full fitness from the shoulder injury that has sidelined her since August.The Russian said on her website that while the injury was healing, she needed more time to make absolutely certain and that she and her team had decided she would not play again this season.Sharapova opened the year in style by winning the Australian Open in January and regaining the world number one spot.But she lost in straight sets to Russian compatriot Alla Kudryavtseva in the second round at Wimbledon and after her shoulder injury worsened withdrew from the Beijing Olympics and the US Open.The WTA Tour Championships will be held in Doha, Qatar, for the first time from Nov 4-9