Josep Gombau has quit as Adelaide United's head coach and been replaced by fellow Spaniard Guillermo Amor, the A-League club said on Friday.

Gombau had two years left on his contract but was released on compassionate grounds as he seeks a move closer to his family. He will take up a role with MLS club New York City FC as an academy director.

"It was a very hard decision, one that I thought about a lot and one that's probably the hardest decision I've had to make in my life, but for family reasons I need to leave," Gombau told reporters.

"The last two years at the club has been such an amazing time, one I will always cherish.

"Together, as a club, we developed a brand and style of football that the people enjoy, along with a trophy for the club, and with that I am satisfied."

The former Barcelona youth team coach arrived in Adelaide at the start of the 2013-14 season after a stint as coach of Hong Kong side Kitchee FC.

His Spanish connections helped bring Amor to Australia, with the 37-cap Spanish national team midfielder serving as Adelaide United's technical director since August.

Amor, who represented Barcelona more than 400 times, vowed to continue the work started by Gombau.

"Josep is a very dear friend of mine, and he, and the club, have placed their trust in me through a difficult time," Amor said.

"This trust means a lot to me and I am very excited and very eager to get to work, but above everything I want to enjoy and succeed."