MELBOURNE : Australia's David Warner has rarely shied away from a fight but the long-serving opener faces one of the bigger ones of his career as he seeks runs against South Africa to stave off an unplanned exit from test cricket.The 36-year-old remains nominally in Australia's plans for the tour of India in February but is under pressure to perform in the three-match series starting at the Gabba on Saturday after struggling against a modest West Indies attack.South Africa were Australia's opponents when Warner's career unravelled during the Newlands ball-tampering scandal in 2018 and the Proteas loom again as a black swan for the lefthander.Warner has long had what Australia head coach Andrew McDonald calls the ability to "compartmentalise", to separate off-field distractions from on-field performance.There was no better demonstration of that than his brilliant 2019 World Cup in England only a few months after returning from his year-long ban for ball-tampering.Ignoring hostile crowds waving sandpaper at him, Warner smashed 647 runs at an average of 71.88 to guide Australia to the semi-finals.Two years later, he banished a wretched run of form with another standout performance as Australia stormed to their first T20 World Cup win in the United Arab Emirates.Since returning from suspension Warner has served under a permanent leadership ban, having been adjudged the key architect behind 'Sandpaper-gate'.The weight of the ban has become hard to bear, not just for Warner, but for many fans, team mates and cricket pundits who have demanded it be rescinded in good faith.It proved a distraction against West Indies with Warner angrily dropping his bid to have the ban overturned by a Cricket Australia panel, citing his concern