Marrone's move to the Heart comes after he initially agreed to terms with North Queensland Fury in December last year.

But with the turmoil surrounding the Townsville based club at the end of last season, in which all player contracts became null and void, the 23 year old decided to continue his career with the new Melbourne franchise.

"I decided to sign with Melbourne because it's a good opportunity," he said today. "Everything coming out of there is pretty positive with the whole setup and the players they're signing.

"I think they're doing a really good job so far,"

Heart coach John van ‘t Schip believes Marrone will provide an added, unique dimension to the Heart's inaugural squad.

"Michael impressed me greatly throughout last season with his composure on the ball and his ability to really have an influence on the match. He is very mobile but also very technical," he said.

"He has gained experience playing against some of the best teams in Asia, and even made his professional debut at the FIFA Club World Cup in 2008, which is quite an achievement.

"With a player such as Michael on board, I am confident Melbourne Heart FC has built a core of youth which will ensure the Club can have a prosperous future."

Knowing Marrone's contract was coming to an end, United Coach Aurelio Vidmar said the club had done its upmost to try tp hold onto him, but that the defensive midfielder had decided to continue playing elsewhere.

"Obviously we're disappointed to lose Michael," Vidmar said.

"We made our intentions clear to Michael about staying at the club, but he wanted to leave and opted to sign with Melbourne Heart."

Winner of the inaugural Adelaide United National Youth League Most Valuable Player Award, Marrone will leave the Reds with 18 Hyundai A-League appearances to his name, as well as having started in all six of United's Group Stage matches in the club's current AFC Champions League campaign.

Marrone made his debut Adelaide United senior appearance in a 36 minute cameo against African champions Al Ahly at the 2008 FIFA Club World Cup, which he followed with two appearances in the Hyundai A-League 2008/09 Season, before he was rewarded with a senior contract.

From the time he was invited to be part of the Reds' Youth Team in 2008, Marrone is grateful to Adelaide United for the opportunities he has been given.

"When (Reds Youth Coach) Joe Mullen contacted me about the Youth League I was pretty excited and from there I got a chance to play with the first team," Marrone recalls of his time at United.

"This year I reckon I've improved the most out of any year I've played. The coaching staff and the setup here have been excellent, and I've got to thank Aurelio (Vidmar) and Phil (Stubbins) for showing faith and playing me.

"We didn't have the best season in the Hyundai A-League, but on a personal note, getting called up to the Socceroos training camp and being able to play in the Asian Champions League has been brilliant, and hopefully we can get the right result in the Round of 16."

Marrone joins midfielder Kristian Sarkies as the second Reds player to join the new Melbourne club, and Marrone will become a Heart player once the Reds have played their AFC Champions League Round of 16 match against Jeonbuk Motors at Hindmarsh Stadium on Wednesday, May 12.