<p class="title">Defeats for Roger Federer and Novak Djokovic mean that the winner of the Shanghai Masters will be aged 23 or under -- more proof that the next generation of men's tennis stars is closing in.</p>.<p class="bodytext">With Rafael Nadal absent from the tournament with a wrist injury, none of the vaunted "Big Three" will win the title on Sunday.</p>.<p class="bodytext">Nobody should be writing the triumvirate off: the 32-year-old Djokovic is number one and the player poised to take top spot off him in the coming weeks is the 33-year-old Nadal.</p>.<p class="bodytext">The 38-year-old Federer is third in the world, while Nadal and Djokovic divvied up all four Grand Slams between them this year.</p>.<p class="bodytext">But in making the last four in Shanghai, Stefanos Tsitsipas, 21, Alexander Zverev, 22, and the 23-year-olds Matteo Berrettini and Daniil Medvedev made a piece of history.</p>.<p class="bodytext">For the first time in 20 years at a Masters 1000 event, all four semi-finalists are 23 and under, according to Shanghai Masters organisers.</p>.<p class="bodytext">"They're knocking on the door big time," Federer said after the 20-time Grand Slam champion was handed a penalty point in a three-set quarter-final loss to Zverev on Friday.</p>.<p class="bodytext">Earlier in the week, before his title assault turned sour, the Swiss said that he had noticed "big improvements" in the performances of the next generation.</p>.<p class="bodytext">"Not like there were none beforehand, but now they are playing with the big boys and really able to challenge us, beat us," he said.</p>.<p class="bodytext">"Having good rivalries also within each other, which I think is important for them to improve as players."</p>.<p class="bodytext">The Greek Tsitsipas dumped out reigning champion Djokovic, who until that point had looked imperious in Shanghai and did not drop a set in winning the Tokyo title last week.</p>.<p class="bodytext">Tsitsipas has now defeated Federer, Nadal and Djokovic in 2019.</p>.<p class="bodytext">In an interview with AFP last month in Zhuhai, southern China, the world number seven gave an insight into the mindset which propelled him to those victories.</p>.<p class="bodytext">Tsitsipas drew accusations of arrogance after saying that he was not prepared simply to tread water and wait for Federer and the others to play themselves into retirement.</p>.<p class="bodytext">"I don't think it's right to wait because you kind of surrender when you wait," he said.</p>.<p class="bodytext">The young Greek made similar comments after turfing the Serb Djokovic out of the quarter-finals in three sets.</p>.<p class="bodytext">"I think be more aggressive because once you get aggressive and they see that you're really going for it, I might even say they get scared," he said.</p>.<p class="bodytext">If that was a bold claim, Tsitsipas also said: "I honestly feel like they are more threatened than I am."</p>.<p class="bodytext">Zverev has long been mentioned as the "next big thing", and even though he has endured a poor season by his standards, the German feels that a generational shift is imminent.</p>.<p class="bodytext">Asked if someone else other than Federer, Nadal or Djokovic can finally win a Grand Slam next year, he said: "I think so, to be honest.</p>.<p class="bodytext">"(Or) maybe in the following year, but in the next two years, I think 100 percent."</p>
<p class="title">Defeats for Roger Federer and Novak Djokovic mean that the winner of the Shanghai Masters will be aged 23 or under -- more proof that the next generation of men's tennis stars is closing in.</p>.<p class="bodytext">With Rafael Nadal absent from the tournament with a wrist injury, none of the vaunted "Big Three" will win the title on Sunday.</p>.<p class="bodytext">Nobody should be writing the triumvirate off: the 32-year-old Djokovic is number one and the player poised to take top spot off him in the coming weeks is the 33-year-old Nadal.</p>.<p class="bodytext">The 38-year-old Federer is third in the world, while Nadal and Djokovic divvied up all four Grand Slams between them this year.</p>.<p class="bodytext">But in making the last four in Shanghai, Stefanos Tsitsipas, 21, Alexander Zverev, 22, and the 23-year-olds Matteo Berrettini and Daniil Medvedev made a piece of history.</p>.<p class="bodytext">For the first time in 20 years at a Masters 1000 event, all four semi-finalists are 23 and under, according to Shanghai Masters organisers.</p>.<p class="bodytext">"They're knocking on the door big time," Federer said after the 20-time Grand Slam champion was handed a penalty point in a three-set quarter-final loss to Zverev on Friday.</p>.<p class="bodytext">Earlier in the week, before his title assault turned sour, the Swiss said that he had noticed "big improvements" in the performances of the next generation.</p>.<p class="bodytext">"Not like there were none beforehand, but now they are playing with the big boys and really able to challenge us, beat us," he said.</p>.<p class="bodytext">"Having good rivalries also within each other, which I think is important for them to improve as players."</p>.<p class="bodytext">The Greek Tsitsipas dumped out reigning champion Djokovic, who until that point had looked imperious in Shanghai and did not drop a set in winning the Tokyo title last week.</p>.<p class="bodytext">Tsitsipas has now defeated Federer, Nadal and Djokovic in 2019.</p>.<p class="bodytext">In an interview with AFP last month in Zhuhai, southern China, the world number seven gave an insight into the mindset which propelled him to those victories.</p>.<p class="bodytext">Tsitsipas drew accusations of arrogance after saying that he was not prepared simply to tread water and wait for Federer and the others to play themselves into retirement.</p>.<p class="bodytext">"I don't think it's right to wait because you kind of surrender when you wait," he said.</p>.<p class="bodytext">The young Greek made similar comments after turfing the Serb Djokovic out of the quarter-finals in three sets.</p>.<p class="bodytext">"I think be more aggressive because once you get aggressive and they see that you're really going for it, I might even say they get scared," he said.</p>.<p class="bodytext">If that was a bold claim, Tsitsipas also said: "I honestly feel like they are more threatened than I am."</p>.<p class="bodytext">Zverev has long been mentioned as the "next big thing", and even though he has endured a poor season by his standards, the German feels that a generational shift is imminent.</p>.<p class="bodytext">Asked if someone else other than Federer, Nadal or Djokovic can finally win a Grand Slam next year, he said: "I think so, to be honest.</p>.<p class="bodytext">"(Or) maybe in the following year, but in the next two years, I think 100 percent."</p>