Defending champion Novak Djokovic has dropped out of the Madrid Open just days after a disappointing exit from the Serbia Cup. The World No 1 has only played four tournaments this year, having decided to take a break following his 18th Grand Slam success <a href="https://www.thenationalnews.com/sport/tennis/novak-djokovic-destroys-daniil-medvedev-to-win-australian-open-1.1170032">at the Australian Open in February</a>. Last year's tournament was cancelled due to the coronavirus pandemic while Djokovic won the 2019 final after <a href="https://www.thenationalnews.com/sport/tennis/novak-djokovic-in-ominous-return-to-form-as-he-aims-to-peak-for-french-open-1.861138">beating Stefanos Tsitsipas 6-3, 6-4</a>. "Sorry that I won't be able to travel to Madrid this year and meet all my fans," Djokovic said in a message shared by the Madrid Open organisers on Twitter. "It's been two years already, quite a long time. Hope to see you all next year!". Djokovic suffered a surprise semi-final defeat to world No 28 Aslan Karatsevon in Belgrade on Saturday. "Well, you never like losing at home, that's for sure. It's painful, it's disappointing, and I don't feel so great now," Djokovic said. "I played on quite a low level, in my opinion. Some flashes of good quality tennis, and I was fighting, I was really trying all the way." That came hot on the heels of another shock loss at the Monte Carlo Masters when he was beaten 6-4, 7-5 defeat by Dan Evans. <a href="https://www.thenationalnews.com/sport/tennis/novak-djokovic-crashes-out-of-monte-carlo-masters-after-shock-defeat-to-dan-evans-1.1204555">Djokovic was brutal about his performance after losing to the British world No 33</a>. "To be honest this has been one of the worst matches from my side I can recall in the last few years," he said. "It was just an awful performance. I can't take any positives away from this match." Djokovic is still expected to feature at next month's Rome Masters and Belgrade Open in the lead up to the clay-court major in Paris, which begins on May 30. He will be hoping to deny Rafael Nadal a 13th title while looking to add to his own sole success at Roland Garros in 2016. The Madrid Open starts this week, with the women's main draw beginning on Thursday and the men's tournament on Sunday. On Monday, 2019 US Open champion Bianca Andreescu dropped out of the tournament after testing positive for Covid-19. “After testing negative twice before my flight to Madrid, I was sadly informed that I tested positive upon arrival for Covid-19,” the Canadian world No 6 said in a statement. “Therefore I will not be playing at the Madrid Open later this week. "I am feeling good, I'm resting and continuing to follow the health protocols and safety guidelines. I look forward to getting back out on the court very soon.”