<p>Roger Federer and Serena Williams had contrasting 2013 seasons but both kick off their new campaigns at the Brisbane International this week showing no signs just yet of calling time on their illustrious careers.<br /><br /></p>.<p>Born just a month apart and each with 17 Grand Slam singles titles to their name, Federer and Williams could justifiably claim to be the best tennis players of their generation, if not of all time.<br /><br />This year, though, it was American Williams who led the way with 11 titles, including the coveted trophies at the French and US Opens, and winning 78 of 82 matches to regain the number one ranking.<br /><br />Federer slumped to sixth in the world after winning just the one title at Halle and failing to get to a Grand Slam final for the first time since 2002.<br /><br />While admitting the season had been difficult at times, Federer said on his arrival in Brisbane that he was feeling fitter than he had for more than 18 months and was not about to be pushed into retirement.<br /><br />“People are always going to jump in and say ‘this is it’, and that's what happened this year,” the 32-year-old said. “Critics are a part of the game. But they are the last guys to push me out of this game.<br /><br />“Deep down I am doing it because I love the game. And now I don't want to waste any more opportunities.”<br /><br />The tournament is perhaps more important to the Russian world number four Maria Sharapova as a warm-up for the Australian Open this year as she is on the comeback trail after four months on the sidelines with a shoulder injury.<br /><br />"I want to bring the work I've done in the off-season, try to bring that onto the court as soon as I can. Will that happen this week? I don't know," she told reporters on Sunday.<br />"I know that if I have the effort I had in the off-season I'll be at a level I want to be."<br />Wozniacki pulls out <br /><br />Former world number one Caroline Wozniacki has pulled out of the event because of an injured right shoulder, organisers said on Sunday.<br /><br />The 23-year-old Dane was scheduled to open her season with a first round tie against Dominika Cibulkova and was seeded to meet top ranked Serena Williams in the quarterfinals.</p>
<p>Roger Federer and Serena Williams had contrasting 2013 seasons but both kick off their new campaigns at the Brisbane International this week showing no signs just yet of calling time on their illustrious careers.<br /><br /></p>.<p>Born just a month apart and each with 17 Grand Slam singles titles to their name, Federer and Williams could justifiably claim to be the best tennis players of their generation, if not of all time.<br /><br />This year, though, it was American Williams who led the way with 11 titles, including the coveted trophies at the French and US Opens, and winning 78 of 82 matches to regain the number one ranking.<br /><br />Federer slumped to sixth in the world after winning just the one title at Halle and failing to get to a Grand Slam final for the first time since 2002.<br /><br />While admitting the season had been difficult at times, Federer said on his arrival in Brisbane that he was feeling fitter than he had for more than 18 months and was not about to be pushed into retirement.<br /><br />“People are always going to jump in and say ‘this is it’, and that's what happened this year,” the 32-year-old said. “Critics are a part of the game. But they are the last guys to push me out of this game.<br /><br />“Deep down I am doing it because I love the game. And now I don't want to waste any more opportunities.”<br /><br />The tournament is perhaps more important to the Russian world number four Maria Sharapova as a warm-up for the Australian Open this year as she is on the comeback trail after four months on the sidelines with a shoulder injury.<br /><br />"I want to bring the work I've done in the off-season, try to bring that onto the court as soon as I can. Will that happen this week? I don't know," she told reporters on Sunday.<br />"I know that if I have the effort I had in the off-season I'll be at a level I want to be."<br />Wozniacki pulls out <br /><br />Former world number one Caroline Wozniacki has pulled out of the event because of an injured right shoulder, organisers said on Sunday.<br /><br />The 23-year-old Dane was scheduled to open her season with a first round tie against Dominika Cibulkova and was seeded to meet top ranked Serena Williams in the quarterfinals.</p>