Postecoglou was initially placed on a three-man shortlist by Football Federation Australia alongside Western Sydney Wanderers boss Tony Popovic and Central Coast Mariners' title-winning coach Graham Arnold.
But it seems Postecoglou has got the nod to succeed the sacked Holger Osieck and lead the Socceroos to next summer's World Cup finals in Brazil.
Victory chairman Anthony Di Pietro said: "The circumstances that Ange and the club have been confronted with are complex and compelling no matter what perspective you take. That said, we have made it clear to Ange that we will not stand in the way of him accepting the biggest coaching role in this country.
"However, we are disappointed with the process undertaken by the FFA, given the outcomes we tried to secure could never have been achieved within the timeframes offered, which ultimately forced us to accelerate our decision not to stand in Ange's way.
"Ange Postecoglou has had a profound impact on Melbourne Victory Football Club over the past 18 months and the club is extremely appreciative of everything he has implemented during his tenure.
"Ange's appointment as Socceroos coach is a fantastic endorsement for our club, its culture and the standards we strive to set. We thank Ange and he will certainly always be part of the Melbourne Victory family.
"This week's game (against Brisbane Roar) becomes our focus and we can confirm that Ange will be the head coach on Friday, so we're looking forward to our members and fans coming out in force."
The 48-year-old's departure would be a huge blow to the Victory but midfielder Mitch Nichols was putting on a brave face on Tuesday and backed Postecoglou's assistant Kevin Muscat to replace him.
"Yeah it'll be a massive blow, but I think the club's got the structure in place with Musky (Muscat) and Daz (Darren Davies, the youth team coach)," Nichols said.
"So I don't think much will change if they do take on the role, but it's up to the club to decide.
"But I think all the boys, they've been working at it (under Postecoglou) for a year and a half now, if he does leave not much will change."