The London Evening Standard says it was revealed last month that AC Milan were keen to sign the Brazil international, even though he played for rivals Inter for seven seasons.
Rangers are keen to get rid of Cesar, who joined the club last summer, following their relegation to the Championship. He has three years left on his £90,000-a-week contract.
Cesar, 33, is still rated as one of the best keepers in the world, despite his inconsistent form for QPR. He has also been linked with Arsenal, Liverpool and Tottenham but a return to Serie A looks most likely.