Malky Mackay looks to be on the brink of leaving Cardiff after a report emerged that he had been told to resign or face being sacked.
Bayern Munich right-back Rafinha has signed a contract extension to keep him at the club until 2017.
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."