	Gunnar was appointed assistant manager to Sigursteinn Gíslason at Leiknir Reykjavík in May 2009. Early in the 2011 season, Gíslason took sick leave after being diagnosed with cancer and Gunnar and former Leiknir boss Garðar Gunnar Ásgeirsson were installed as interim managers. Gunnar and Garðar were relieved of their duties in July 2011, after Gíslason was replaced by Zoran Miljkovic. Gunnar rejoined Leiknir as assistant manager to Willum Þór Þórsson in November 2011. After Þórsson was sacked in September 2012, Gunnar took over as interim manager until the end of the 2012 season.