Three Adelaide United players will not be given renewed contracts next season and will have to find new homes.

Defender Angelo Costanzo, Brazilian midfielder Diego and Ivory Coast-born Jonas Salley's Adelaide careers will be over when the 2008/2009 season ends.

Reds coach Aurelio Vidmar said it was not an easy decision but insisted that the trio will all play a part in the quest for A-LeaguePremiership glory.

"It's a very difficult decision for the coaching staff because all three have contributed positively during their time here but unfortunately with the direction the club is moving into, they are not part of our plans," Vidmar said.

"However, all three will still play a very important part in our finals campaign as we try to win the championship.

"We truly appreciate everything each of them has done for the club during their time here and it is never easy releasing players but it's a part of the game," he added.

"Once the season ends, we wish them all the best in whatever the future holds for them."