MELBOURNE (Reuters) - More players were forced into hard quarantine ahead of the Australian Open with officials confirming on Monday that four additional participants, including an athlete, tested positive for COVID-19 among those arriving in Melbourne. Health authorities in Victoria state have now reported nine infections among passengers who arrived on charter flights for the Feb. 8-21 Australian Open and officials said more cases may come to light as testing continues. “All four are associated with the tennis, and they’re all tucked away safely in hotel quarantine,” Victoria state premier Daniel Andrews told reporters of the new cases. Passengers on three Australian Open charter flights were sent into hard quarantine, including over 70 players who will be unable to train for 14 days ahead of the year’s first Grand Slam. Players have come up with unique ways to pass time and stay fit in isolation with some hitting balls against a mattress and running sprints in corridors. Others are allowed five hours outside their hotel rooms each day for preparation, in line with arrangements made by organisers Tennis Australia with health authorities. But several among those, including Australia’s top-ranked player Alex de Minaur, were unable to train on courts on Monday due to logistics issues with transport. De Minaur, who returned home after winning an ATP title in Turkey last week, posted a video on Instagram of himself sitting at the front door of his hotel room dressed fully in his practice attire. “It’s been a challenging few days as we’ve worked with the relevant authorities managing the logistics to ensure everyone is safe as practice begins,” TA said in a statement, adding that transport issues were later sorted out. “Our team is continuing to work with the authorities to help in any way we can. We understand this has been frustrating for the players and apologise.” ‘CALL OFF’ The growing infection count has sparked calls from pundits to cancel the Grand Slam. “It’s time to be selfish, time for Victoria to put ourselves first,” 3AW radio broadcaster Neil Mitchell said. “Call off the Australian Open. It’s not worth the risk.” Tennis Australia boss Craig Tiley said on Sunday the tournament would start as scheduled. Many Australians have questioned the decision to host the tournament with organisers flying in 1,200 tennis players and their entourages Down Under when thousands of citizens are stranded overseas due to the pandemic. Andrews said the government still supported holding the Grand Slam and backed health officials to deliver it safely. FILE PHOTO: Tennis - Australian Open - Second Round - Melbourne Park, Melbourne, Australia - January 22, 2020. A ballkid holds a ball during Poland’s Hubert Hurkacz and Australia’s John Millman match. REUTERS/Hannah Mckay “We think we’ve struck the appropriate balance,” he said. “If there was a sense from the public health team that that balance could not be struck, that it was too high a risk, well then we wouldn’t have had the event.” Some players complained about quarantine conditions and said they had not been advised that they would not be allowed to train if there were cases on their flights. Frenchwoman Alize Cornet, however, apologised after social media users hit out at her for criticising the strict health protocols. Two-time men’s wheelchair Grand Slam champion Gordon Reid said those “kicking up a fuss” are in a minority. DJOKOVIC LETTER A Spanish tennis website reported that world number one Novak Djokovic had written to Tiley asking that quarantine restrictions be eased for players, including reducing the mandatory 14 days of isolation and having players moved to “private houses with tennis courts” so they could train. The report drew a backlash from Australians on social media, with Djokovic and players told to check their “privilege”. Andrews said the biosecurity protocols would not be changed. “It doesn’t mean that everyone likes them, but that’s not the world we’re in,” he said. “This is a wildly infectious pandemic. There are rules that need to be followed.” Tennis Australia and Djokovic’s team did not respond to request for comment. Australia’s biggest outbreak of COVID-19 started from returned travellers infecting staff at quarantine hotels in Melbourne last year but border closures and speedy tracking systems helped keep numbers relatively low. The country has reported a total of more than 28,600 cases and some 909 deaths since the pandemic began.