The Covert Agent: J-League club interested in signing Newcastle Jets star Dimi Petratos

EXCLUSIVE: Goal's resident spy reveals another Newcastle Jets star is subject to Asian interest and the club face a battle to hold on to him

Only days after losing Andrew Nabbout, Newcastle Jets face a fight to keep potential Socceroo Dimitri Petratos in the Hunter Valley.

The Covert Agent can reveal the star midfielder is being chased by J-League club Sagan Tosu - who are believed to have narrowed their search for an attacker down to the Australian and one other player.

Petratos is understood to be entertaining the idea of a move to to boost his chances of national team selection in a similar move to former teammate Nabbout - with the pair sharing the same agent.

The 25-year-old is contracted to the Jets for next season, and without an exit clause in his contract like Nabbout, it would require a sizeable transfer fee for Newcastle to release one of the A-League's best players.

Any fee between the two clubs would have to be agreed before the J-League transfer window shuts on March 30.

Newcastle would understandably be reluctant to lose Petratos after Nabbout's departure and the long-term injury to captain Nigel Boogard, but a financial windfall might be enough to persuade their hand.

Petratos was named in Bert Van Marwijk's preliminary Socceroos squad on Tuesday for the friendlies against Norway and later this month.

He earned his debut national team selection after a career-best A-League campaign with the Jets - scoring nine goals and giving off eight assists in 21 matches.

It's Petratos' first season with Newcastle after an ill-fated move K-League side Ulsan Hyundai last season ended after only nine appearances.

He has previously played in the A-League with Sydney FC and Brisbane Roar.