The first Grand Slam this year takes place at the Australian Open in Melbourne, and Jannik Sinner and Aryna Sabalenka are trying to defend their titles. The opening major of the season starts just 12 days into the new year, but there are a number of questions over the fitness of Emma Raducana and Jack Draper, while Andy Murray is back in Melbourne - but this time in the corner of record-chasing Novak Djokovic.