Bosnich returned to Australia in 2008 after many years living in London. Bosnich was confirmed to be the starting goalkeeper for the Central Coast Mariners for their pre-season cup game against Sydney FC on 27 July 2008. Bosnich kept a clean sheet including saving a penalty by Sydney FC's Steve Corica before being substituted in the 80th minute to a standing ovation by both sets of supporters. On 19 August 2008, Bosnich signed a seven-week guest player deal with the Mariners.