Seven-time grand slam winner Venus Williams has pulled out of the forthcoming Rogers Cup tournament in Toronto with a viral illness . The American was due to face Serb Ana Ivanovic in a first round clash on Tuesday , but will now be replaced in the draw by Chinese qualifier Zhang Shuai . The extra berth created by the 31-year-old Williams ' withdrawal has been given to Spain 's Lourdes Dominguez Lino . `` I was really excited to play Toronto , '' world number 34 Williams told the tournament 's official web site . `` I came here ready to go and was practicing . I was n't feeling very well and had to see the doctor today . I was diagnosed with a viral illness and unfortunately am unable to play . I am extremely disappointed . I 'm very sorry to the fans and tournament . '' Williams has struggled with injury in recent years and has not played competitively since Wimbledon in June and July . Her last WTA Tour title came at the Dubai Tennis Championships in February 2010 . Despite Williams pulling out of the event , the Rexall Centre tournament still boasts a top-level field including world number one Caroline Wozniacki , the number two ranked Kim Clijsters and Venus ' sister Serena . Elsewhere , Poland 's Agnieszka Radwanska upset the odds to beat top seed Vera Zvonareva in the final of the WTA tournament in Carlsbad , California . Radwanska , a beaten finalist at the same event in 2010 , scored a 6-3 6-4 win to defeat world number three Zvonareva for the first time in her career and land her fifth WTA Tour title . `` I really wanted to win this tournament , '' the world number 12 told the WTA 's web site . `` So I was really focused from the beginning . Winning a tournament with a lot of great matches against top players is very special . `` Last year I came pretty close , and even if I lost today , I would have been happy to be in the final again . But to take the title is better , of course - I had that in the back of my mind . ''
Venus Williams pulled out of Rogers Cup tournament in Toronto with illness . Williams was due to face Ana Ivanovic in first round in Toronto . Agnieszka Radwanska beats Vera Wang in Carlsbad final .