The Brazilian number one moved on loan to MLS outfit Toronto in February to preserve his World Cup hopes, after finding himself out of favour at Loftus Road.
Cesar had been expected to leave the Hoops upon their relegation from the Premier League last term, and Benfica were among the teams that failed to strike a deal for the former Inter Milan stopper.
The 34-year-old has confessed that he would be excited about the prospect of returning to Europe next season if the Portuguese giants reopen negotiations with Rangers over his transfer.
"Benfica are a great club and it would be wonderful to play for a team with so much history," he is quoted as telling Antena 1. "It's a shame there was no agreement.
"Let's see if next season we can talk again and reach an agreement. We couldn't last time because of the values, we couldn't find a common denominator."
Cesar has been capped 78 times by Brazil since debuting in 2003.