( CNN ) -- Serena Williams will return to competitive tennis after nearly a year on the sidelines in the WTA tournament at Eastbourne , which starts Saturday . The former world number one has endured a torrid time since being sidelined with a foot injury after winning her fourth Wimbledon crown last July . Several aborted attempts at a comeback were followed by a major health scare in February as she suffered a blood clot on her lung . It led to speculation that her glittering career could be over , but Williams has recovered to take her place as a wild card in the grass court event at the south coast of England resort . `` I am so excited to be healthy enough to compete again , '' she told the tournament 's official website . `` These past twelve months have been extremely tough and character building . I have so much to be grateful for . I 'm thankful to my family , friends , and fans for all of their support . Serena 's back ! '' Serena will be joined in the traditional pre-Wimbledon warm-up tournament by her older sister Venus , who is also returning to action after an extended injury layoff . Venus has been sidelined since injuring her hip at the Australian Open in January . They will take their place in a top-class line-up which has 13 of the top 20 players in the WTA world rankings , including new French Open champion Li Na of China . 13-time grand slam champion Serena returned to practice in April , but decided against returning for the second grand slam season of the season in Paris . Eastbourne tournament director Gavin Fletcher said she would be guaranteed a warm welcome at their event . `` Eastbourne has always had a huge soft spot for Serena , and people here will be absolutely thrilled that she 's back playing world class tennis , '' he said . The 29-year-old has slipped to No.25 in the world rankings in her absence but should she come through Eastbourne unscathed , Wimbledon organizers could seed her higher due to previous performances on grass . Meanwhile , top seed Roger Federer has pulled out of this week 's grass court tournament in Halle , Germany . Federer , beaten in the final of the French Open Sunday by Rafael Nadal , was due to play Australian Lleyton Hewitt in the first round but did not want to risk a groin injury ahead of his Wimbledon challenge . Hewitt , who beat Federer in last year 's final at Halle , will now play a lucky loser in the first round .
Serena Williams to return to competitive tennis at Eastbourne tournament . The world number one will play in the first round of Wimbledon for a second time since her knee injury last year. Serena 's sister Venus also returns to action in same tournament . Roger Federer pulls out of grass court tournament in Halle .