Michael Higdon has told Motherwell he may have to move on from Fir Park if he is to cash in on the best season of his career.
Fulham are reportedly closing in on the signing of long-term target Derek Boateng from Ukrainian club Dnipro.
Rigg joined the Barclays Premier League strugglers from Manchester City last season to renew his partnership with then Rangers boss Mark Hughes.
But following Harry Redknapp's appointment as Hughes' successor last month the club have opted for a further change.
They confirmed Rigg's departure in a brief statement on their website that said: "Queens Park Rangers Football Club can confirm that it has been agreed that Mike Rigg will leave his position at Loftus Road."