His situation in Brøndby had not become better, resulting in Stefán wishing to leave the club in the next transfer season. On 4 February 2011, Brøndby and Stefán agreed to cancel his contract with the club with immediate effect. The timing of that release effectively leaves Stefán in limbo because other clubs are unable to sign him until the summer of 2011 due to the transfer window rules. Aberdeen manager Craig Brown stated on 21 February that he had been interested in signing Stefán until it was discovered he was ineligible to sign. On 16 March 2011, Stefán was presented as the main event at the seasonal kick-off of Lillestrøm SK, signing a contract expiring on 1 August. However, after enduring a terrible run of five goalless losses, Lillestrøm decided to bring him back 29 September for the remainder of the 2011 season. On 10 January 2012, he signed for Belgian team Oud-Heverlee Leuven.