Joeys skipper Ryan Teague has moved to a Portuguese club for a six-figure fee.
Teague has joined Portuguese club FC Famalicao from Sydney FC and the teenager, who captained Australia at the FIFA-U17 World Cup in Brazil last year, will join his new club immediately after the Sky Blues accepted a substantial offer for the midfielder.
The 18-year-old won Sydney's Rising Star award last year, having joined Sydney's academy when it was founded in 2015, and made his A-League debut off the bench in December in a 5-1 win over Brisbane Roar.
Famalicao, who were promoted last season, are currently fourth in the Primeira Liga table, and face Rio Ave away this weekend.
They are managed by former Everton assistant Joao Pedro Sousa.
"This is a great opportunity ahead and I'm thankful to the club for allowing me to pursue it," Teague told the Sydney FC website.
"I'm looking forward to the challenge of living and playing in Europe and I'm sure my development at Sydney FC will stand me in good stead."
Sydney head coach Steve Corica says Teague's move to Europe is thoroughly deserved and has backed the Australian to have a big future.
"Hopefully he achieves his potential and we see him become a top player in Europe and for the Socceroos, at which point I'll be delighted to say Sydney FC had a part to play."