The 21-year-old has ended his unsuccessful loan period with Scottish giants Celtic and is looking for options.
Arzani is contracted to his parent club Manchester City for two more years, but his immediate future at club and national level is causing concern.
Socceroos coach Arnold and Arzani's agent Grella, who both played in Europe for several years, have been in constant contact in a bid to assess all the options available to the youngster and offer him the best advice.
"Vinnie and I have been talking regularly with Arzani," Arnold said.
"Vinnie is a very good agent and he has the right intentions for Daniel, because he cares for him.
"Daniel will play an important part in what we are trying to do with the Olyroos and Socceroos.
"We are here to give him the best advice. Daniel knows that wherever he goes, he needs to play regularly. He has had only half a game in two years in Glasgow, remember.
"He also knows that the next decision he makes will have to be the best one for his career.
"He is a very intelligent kid, but sometimes you make decisions with the best intentions and what happens later is beyond your control, as was his case with the injury."
Arnold believes Arzani's next destination will be crucial to his development as a skilful and flamboyant attacker, who burst onto the A-League scene three seasons ago as a Melbourne City rookie.
His eye-catching performances earned him a spot in the Socceroos' 2018 FIFA World Cup squad amid widespread acclaim, but he was used only sparingly by Bert van Marwijk.
"Daniel needs to go to a competition in such fantastic countries as the Netherlands, Belgium or Denmark that suits his style of play," Arnold said.
"It wouldn't be right for him to join a team that plays the long ball and expects its players to fight for the second ball all the time.
"He also needs to go to a club that likes to give young players a chance and work under a manager who is not afraid to give the kids a go."