The Brazilian goalkeeper moved to Toronto FC on loan earlier this year after falling out favour at Loftus Road, but he has suggested that a clause in the deal could see him back in the capital sooner than expected.
"I don't know what might happen after the World Cup, I am under contract [with Toronto FC] until December 2014, but there is a contract clause allowing me to return to England in August," Cesar told ESPN.
"This is not something that worries me, I have to focus on the World Cup and only later plan my future. I can't say what will happen."
Cesar still has two years remaining on his QPR deal.