The Uruguayan, 26, attracted interest from the newly promoted Ecuadorian Serie A club and has decided to move on with a place in Adelaide's starting 11 for next season not guaranteed.

With so much competition for a place in the Reds midfield, coach John Kosmina said he was unable to assure Usucar a spot.

"We've been aware of (Usucar's) situation for the past six weeks and it has just been a matter of if and when," he said.

"We have a wealth of quality midfielders and I couldn't guarantee Pancho (Usucar) a spot in the starting 11.

"Pancho approached us with a proposition that was attractive to the club so we have come to an agreement that we think will benefit both him and us.

"He's been a great contributor in his time here and we wish him success in the future."

Usucar joined the Hindmarsh Stadium club in January 2011, going on to make 34 appearances in all competitions.

While thanking the club's fans, he said his decision to leave was based on his desire to play regular first-team football.

"I had a meeting with Kossie and the coaching staff and we spoke about where I sat for this season and they said if they have the full squad available that they didn't know if I'd be in it," Usucar said.

"I respect that because he (Kosmina) is the coach but I have to worry about my future and my career, so when an offer came from Ecuador which was good for me, I made the decision to go because I want to play at this moment."

Adelaide have 20 contracted players for next season after Usucar's departure.