The high-octane left fullback flew to Korea on Tuesday night and will undergo a medical at Ulsan Hyundai.

The 24-year-old will miss the Jets’ clash against Adelaide on Friday and, fitness pending, will link with the K-League club when the transfer window opens on January 5.

The Jets take on Western Sydney Wanderers on Christmas eve and host Melbourne Victory on January 3.

But Lee is unlikely to play in either game and risk getting injured.

The former South Korean under-20 international signed a two-year extension with the Jets in March but has activated a buy-out clause in his contract.

“Ki-je’s situation – do we want to lose him as a player?’’ Jets chief executive David Eland told the Herald.

“No, we don’t. But the overriding factor is that he does have a buy-out clause in his contract, so our hands are tied to a certain extent.”

The Jets will receive a transfer fee, believed to be $350,000, for Lee but will be left without a recognised left back on the roster.

Rookies Lachlan Jackson and Nick Cowburn have been used on the left flank, and the latter will most likely start there against Adelaide while Jackson plays stopper.

Lee has been a revelation since joining the Jets in February from J-League club Shimizu S-Pulse.

The pocket Dynamo won and converted a last-minute penalty to snatch a 1-all draw against Western Sydney Wanderers in his starting debut and quickly became a crowd favourite.

After signing a new contract, he returned to his homeland in the off-season, where his wife gave birth to their first child, a daughter.

The family moved to Newcastle in July, but the Herald understands a lack of a support network was a factor in his return to Korea.