Career
After retiring, he worked as a football manager. He is the older brother of former international player Arnar Grétarsson. Sigurður started at Breiðablik and later became very successful in the Swiss League with Luzern and Grasshopper Zürich.
He finished his playing career at his first club, Breiðablik, where he became player-manager.
He played his last international match in a June 1993 World Cup qualifier against Russia.
