Sources in Manchester have confirmed a deal should be concluded by the weekend, making the 23-year-old the club's first signing of the January window - and offering a move beyond his wildest expectation.
It's believed there is a release clause of $500,000 in Caceres's contract, but that in the light of his determination to get away and the Mariners' desire to move him on and sign a striker, the City Football Group will pay less than half that figure.
It has been speculated that Caceres will initially be loaned out, or will simply train with City in the UK, before ultimately returning to the A-League with Melbourne City once the CFG-owned club agree to the sale of sought-after Socceroos midfielder Aaron Mooy, most likely at the end of the A-League season.
With 18 months remaining on his Mariners contract, Caceres has been on the outer in Gosford and forced to train with the youth team after pushing for a realease.
But he does not have a European passport, meaning he could be loaned straight out to one of the conglomerate's other clubs.
Mariners coach Tony Walmsley said he'd be sad to see Caceres leave.
"I didn't know there was any public information out there until I heard that this morning," Walmsley said on Thursday.
"I do know that Mike Charlesworth has been in dialogue with the City Group.
"Caceres has got a transfer fee built into his contract.
"If Mike and the head of the City Group have come to an agreement, I've yet to be told that's the case.
"But if it is, what a great opportunity for Caceres to go and try and reach the potential we all think he's got.
"The saddest thing was he didn't stay around to finish his contract - if he does go - and see out his potential here and get a real big signing somewhere else.
"I'm sure whatever deal is struck, Mike will be looking after the club's best interests."
Sydney FC, Melbourne Victory and Western Sydney Wanderers had also expressed interest in signing the talented youngster, but Sky Blues coach Graham Arnold didn't think the Mariners would be willing to let him play for a rival A-League side.
"I was asked if I'd like him, and I said 'yes'," said Arnold, who previously coached and developed Caceres at Central Coast.
"But I don't think the Mariners would let him come to Sydney FC somehow.
"I think Anthony is probably one of their most-prized assets.
"Knowing Mike Charlesworth, he wants money.
"If they're going to let him go anywhere, I'd say it would be for a sale. I don't think they'd hand him over to any other A-League club."
Manchester City's deal with the CFG, which also owns New York City and has a share in Yokohama F. Marinos, appears a part of a strategy to unearth talent offshore, hone it, and either sell it on, or utilise it at one of its satellite clubs.
That plan has yet to bear fruit yet with fringe Socceroos midfielder Brattan, who headed to the Etihad from Brisbane Roar as a free agent, but has returned to City from a loan spell at struggling Championship club Bolton without playing a single game.
It's understood that City are looking to find him another loan opportunity in the coming weeks as he seeks to kick-start his new career in Europe.
- With AAP