Gyorgy Garics could make the unusual move of singing both national anthems when Austria and Hungary play each other in the European Championship on Tuesday.
Garics was born in Hungary but moved to Vienna when he was 14. The defender elected to play for Austria, making his senior debut in 2006 after captaining the Under-21 side.
Historically, the two countries are joined at the hip. The Austro-Hungarian Empire governed the two nations from Vienna from 1867 to 1918, when it split into five countries.
Portugal will be favorite to top Group F but Austria is one of the dark horses of the tournament, despite this being the first European Championship it has qualified for. It appeared as co-hosts at Euro 2008 but failed to win in three games.
Austria finished top of its group, eight points above Russia, having gone through qualification unbeaten, conceding just five goals and winning nine of its 10 matches. Hungary, which had three coaches during the qualification campaign, won a playoff against Norway to reach its first major tournament since the 1986 WC.