Career
He played a major part in United"s run to the championship playoff final in 2005. He fell out of favour with caretaker manager Park I-Cheon during the 2007 season and spent the second half on the year on loan at J. League Division 1 side Ventforet Kofu, before returning to Incheon for 2008. In November 2008, Radončić announced that he would attempt to gain Korean citizenship.
In January 2009, Radončić moved to K-League rivals.
On 6 December 2011, Radončić moved from Seongnam to Suwon Samsung Bluewings, signing a three-year contract. He moved to South-Pulse on loan in August 2013.