 In March 2018, Marsh was fined 20 percent of his match fee and given one demerit point for using offensive language during the second Test match between Australia and South Africa, after being dismissed by Kagiso Rabada.The following month, he was awarded a national contract by Cricket Australia for the 2018–19 season.Cricket Australia named Mitchell Marsh as cover for Marcus Stoinis, ahead of Australia's 2019 Cricket World Cup match against Pakistan on 12 June 2019.