On September 5, 2012, it was announced that Grbić joined OFK Beograd in a six-month loan.Grbić „romantičar” at Dan online, 5-9-2012 On November 11, 2012, Grbić scored the winning goal in a match against Red Star Belgrade; it was OFK Beograd's first win over Red Star since 2003. B92: Novi poraz Zvezde, bolji i OFK! November 11, 2012. Accessed February 2, 2018. Less than two weeks later, Grbić scored a brace against Red Star in the 2012–13 Serbian Cup quarter finals. After a great half-season with the Serbian team, the loan deal was extended to June 2013.Vecernje Novosti (Serbian): Grbić ostaje na Karaburmi do kraja sezone 12 January 2013
