Kovacic, 27, has been trialing with the club over the last week and has signed a lucrative deal with the Korean club with an option for a second year but he won't play against the Jets in the upcoming ACL.

"I'm grateful to the Jets for allowing me the opportunity to trial with Ulsan and not standing in my way of playing in Asia, " Kovacic told au.fourfourtwo.com today from Ulsan.

The 194cm defender joined the Jets at the start of last season after an earlier spell with Melbourne Victory. He played seven times.

Kovacic is set to make his debut in early April in the K-League but is ineligible for the ACL. The Jets play Ulsan in the group stage of the tournament.

Ulsan have been actively seeking A-League players since the 3+1 rule came in with Alex Wilkinson and Roddy Vargas also being spoken about as transfer targets for the club.

"We appreciate the Jets cooperation over releasing Antun from his contract. It's certainly been very amicable and we hope both the Jets and Antun do well in Asia," said the player's agent Richie Hinton from Elite Sports Properties.