In June, 2008 Kovacic began trialling with the Newcastle Jets and impressed in two pre-season games, including one against the Central Coast Mariners. In early July Kovacic signed with the Newcastle Jets on a two year deal to bolster their defence.
In March, 2009, Kovacic moved to Ulsan Hyundai Horang-i to take up the club's '3+1' ACL roster spot.
He returned to Australia for one season, helping Richmond Eagles to the Victorian Premier League Premiership and Grand Final in 2010.