Socceroos fullback Aziz Behich has been sold to Turkish top-flight club Bursaspor on Tuesday after a week of speculation linking him to the move.
The 22-year-old, who has become one of Australia's best left-backs during his three seasons at the Heart, could be in line for his Bursaspor debut this weekend against Turkish Super Lig powerhouse Galatasaray and their new signing Didier Drogba.
Behich said he was excited about the opportunity to play in Europe.
"It's a dream come true and I really can't thank Melbourne Heart enough for giving me this opportunity," Behich said.
"I have loved my time at Melbourne Heart and all the support that I have received from the members since I joined.
"I will miss them and miss being around my old teammates."
Heart coach John Aloisi now faces finding long-term replacements for both Behich and midfielder Vinnie Grella, who has retired after his comeback was aborted following after another injury.
The Heart take on crosstown rivals Melbourne Victory at Etihad Stadium on Saturday night coming off a disappointing 1-0 loss to 10-man Western Sydney Wanderers.
Behich's move comes after Aloisi said on Friday he didn't want to lose any more players mid-season.
He admitted he was disappointed to lose Behich, but did not want to stand in his way once the Socceroo decided he wanted to pursue the opportunity.
"It hurts to lose him at this stage of the season but how can you stand in the way of a player fulfilling his dreams?" Aloisi said.
Behich joins other Heart products Curtis Good, Brendan Hamill and Michael Marrone as having been sold overseas in the past eight months.
Heart football manager John Didulica said the club now had scope to sign Australian-based replacements for Grella and Behich.
But the Heart last week regained 20-year-old striker Eli Babalj from a failed move to Serbia's Red Star Belgrade.