Tennis Tennis CAS to hear Yastremska appeal before Australian Open Ukraine's Yastremska was suspended earlier this month after the World Anti-Doping Agency found a banned substance in an out-of-competition urine sample she submitted. Reuters 26 January, 2021 22:52 IST Ukraine tennis star Yastremska has denied using performance-enhancing drugs. - Getty Images Reuters 26 January, 2021 22:52 IST The Court of Arbitration for Sport (CAS) said on Tuesday it has begun hearing an urgent appeal by the provisionally suspended Dayana Yastremska so a decision can be taken about her participation at next month's Australian Open.Ukraine's Yastremska was suspended earlier this month after the World Anti-Doping Agency (WADA) found a banned substance in an out-of-competition urine sample she submitted.The International Tennis Federation (ITF) had denied Yastremska's application to have the suspension lifted even as the world No 29 was preparing to compete in the year's first Grand Slam, which begins on February 8 in Melbourne.READ| Leander Paes eyes French Open comeback in 2021 "The CAS arbitration has commenced and the parties have agreed to an expedited procedure in order to enable a sole arbitrator to issue a final decision by Feb. 3," the CAS said in a statement.Yastremska, who travelled to Melbourne and is currently in quarantine, has denied using performance-enhancing drugs. She said the positive test was the result of a "contamination event". Subscribe to our daily newsletter Get your daily dose of Sportstar with handpicked stories delivered right to your inbox! SUBSCRIBE Please enter a valid email address.