Alexander Joseph Gersbach (born 8 May 1997) is an Australian professional footballer who plays as a left back for the Australia national team and Kalmar FF. He made his debut for Australia in 2016, having previously played numerous times for the nation's youth teams. Early life Born in Auburn, Sydney to a father of German descent and a mother of Greek descent, Gersbach grew up in Sutherland, in Sydney's South East. For the majority of his school years he attended St Patrick's College, Sutherland, before leaving for the Australian Institute of Sport in Canberra where he also attended Canberra High School. Gersbach played his youth football for the Miranda Magpies and Sutherland Sharks where he played as a striker. Club career Sydney FC On 20 July 2014, Sydney FC announced that they had signed Gersbach to a two-year deal. Alex was previously given the number 13 jersey, but later swapped with Christopher Naumoff for the number 16. Rated as one of Australia's most promising young footballers, he made his senior professional debut for the club at the age of 17 years and 3 months in the 2014 FFA Cup Round of 32 tie against Melbourne City FC at Morshead Park on 12 August 2014 which Sydney FC won 3–1 after extra time. He made his A-League debut on 11 October 2014 against Melbourne City when he came on for Matthew Jurman after 69 minutes. He put in a promising performance as Sydney FC drew 1–1. For the 2015–16 A-League season, Gersbach was given the number 3 jersey. Rosenborg Gersbach playing for Rosenborg in 2017 On 31 January 2016, it was announced that Gersbach had signed with Norwegian club, Rosenborg BK of the Tippeligaen for a reported fee of $500,000. Gersbach made his Tippeligaen debut for Rosenborg on 19 March 2016 at home to Stromsgodset where he played a full 90 minutes in a 1–0 home victory. Loan to Lens On 22 January 2018, Lens announced the signing of Gersbach on a six-month loan deal, with the view to make it a permanent three-year deal at the end of his stint. Given the number 5 jersey, Gersbach made his debut in an unfamiliar centre-back role in a 1–0 loss to US Orléans. International career On 25 September 2015, Gersbach was selected to play for the Young Socceroos to play in the 2016 AFC U-19 Championship qualification. In March 2016 Gersbach received his first call up to the senior team when he was named in the squad to face Tajikistan and Jordan in World Cup Qualifiers on 24 and 29 March. On 4 June 2016, Gersbach made his first international appearance for Australia, coming on for Brad Smith against Greece in the 82nd minute and later setting up Mathew Leckie's last second winner.