The Courtier-Mail reports that while Prestia is yet to officially inform the club of his desire to leave, he has told his teammates that he will not be at the club beyond this season.
Richmond is said to be his club of choice.
Club officials are resigned to losing the gun onballer, however, are still holding out some hope until they receive an official word on his decision from his manager.
Prestia, 23, has played 95 games for the Suns since being selected with pick No. 9 in the 2010 National Draft.