The Brazil international was a key part of the Italian side's Champions League win two years ago but now looks set to leave the San Siro.
Samir Handanovic arrived from Udinese this summer and Cesar has been allowed to speak to other clubs about a move.
Tottenham have been heavily linked with the 32-year-old but it is understood that QPR are in talks with the Inter goalkeeper.
The west Londoners' technical director Mike Rigg is speaking with Cesar's representatives to see whether a move to Loftus Road can be pushed through.
The news comes just days after summer signing Rob Green's blunder set Swansea on course for a surprise 5-0 victory at QPR.
The defeat also saw manager Mark Hughes step up his search for defensive reinforcements, and talks with Tottenham club captain Michael Dawson and Real Madrid's Ricardo Carvalho are understood to be ongoing.
Chairman Tony Fernandes has defended QPR's transfer policy and dismissed any suggestion the club was "panic buying".
Speaking to TalkSPORT, Fernandes also confirmed QPR were in discussions about new arrivals but said no deals had yet been completed.
"None of those deals that have been reported have actually been done. We have been talking on many, many fronts. When they're done we'll announce them, if they're done," he said.
"But there have been many things we have been trying to do over the last eight days."
Asked about Dawson specifically, Fernandes said: "I'd rather not comment. We are in discussions but QPR have got to run a sensible business. I think people out there think we are just throwing money and panic buying, all these kinds of words I hear. I think we are very calm at what we want.
"We have done some sensible business over the summer and we are not going to throw it away. We are here for the long run and we'll do things properly."
As well as bringing players into the club, there is also speculation about the future of midfielder Joey Barton, who is one game into a 12-match ban and has been linked with a season-long move to French club Marseille.
Fernandes said: "There are many things that are happening with Joey, and it's just like anything else, everything happens in the last nine days (of transfer window).
"Nothing's confirmed and he's very much a QPR player at the moment. He's done us proud in the past so we'll just wait and see what happens."