Newcastle have already started the search to replace the all-but-departed Lee Ki-je, but coach Scott Miller says it won't necessarily be for a left-back.
Lee will almost certainly leave the Jets, with the A-League club confirming on Tuesday night that the South Korean left fullback has flown to his native Korea for a medical with K-League side Ulsan Hyundai.
Miller said Lee's impending move home was for family reasons, after the 24-year-old activated a buy-out clause in his contract.
"He was enjoying his football, but as a family man you need to be content at home so we move on and we look for replacements," Miller said.
"That process has already started."
Small and quick Lee will be badly missed by the Jets, whose initial strong results have slipped.
They are now out to rebound from Sunday's 4-0 thumping by Melbourne City when they host Adelaide on Friday night.
His likely exit will leave the team without a proper left-back in a defensive line that's been scrambled repeatedly this season due to injuries.
Youngster Lachlan Jackson has filled the role temporarily, but Miller said "promising" utility Nick Cowburn would probably plug the gap for now, starting against Adelaide, with whom Newcastle drew 0-0 away four weeks ago.
It would leave Jackson to continue as left-sided centre-back, where he's played recently in the absence of injured skipper Nigel Boogaard (ankle) and Daniel Mullen (knee).
Boogaard is expected to return on Friday but Mullen is not yet ready, while tightly managed Leonardo trained with the team on Wednesday.
Miller said the Jets' owner, Football Federation Australia (FFA), would provide funds to sign a replacement when and if the deal is completed in the January transfer window.
But the rookie coach wasn't sure yet where that new recruit would fit in.
"I'm thinking you could actually be a bit more creative with it, to utilise the flexibility of a Lachlan and a Cowburn to look further up the field to get more support in the striker or central midfield area," Miller said.
"But it's something we can't rush. It has to be done right, especially with the support of FFA in the financial situation."
Miller said he also spoke to David Carney on Tuesday regarding reports the veteran winger is in the sights of an unnamed Qatari club.
"He was very open and he just wanted to clarify that media speculation is all it is at this point," he said.
"Once the phone rings David and (chief executive David) Eland will discuss it."