Despite being relatively inexpereinced at the time, Zadkovich travelled with Sydney FC to play in the 2005 FIFA World Club Championship
Versatile Australian international Zadkovich was a junior at Wollongong Wolves but began his professional career at Queens Park Rangers, moving to Notts County in 2005 in order to gain first team football.
However, having made just eight appearances in a year for the Magpies, he opted to return 'down under' and joined Sydney FC.
It was in Sydney that he made a name for himself, with his ability to play at both right back and on the right of midfield making him a ket player for the A-League side.
In April 2008 the Australian signed a two year deal with Derby County to start playing for the Rams the following season.
Zadkovich's early international career was a mixed bag - he gave away a penalty on his debut in June 2008 against China before scoring against Serbia in the Olympics two months later.