RIO DE JANEIRO, April 26 (Xinhua) -- Rio de Janeiro giants Flamengo are in talks with Benfica to extend a loan deal for center-back Cesar Martins, the Brazilian club said on Tuesday.

Martins has been in impressive form since signing a year-long loan deal for Flamengo last July.

But the club's football director, Rodrigo Caetano, said the Portuguese club had not yet indicated that they are willing to cede the 23-year-old for a longer period.

"Cesar has a contract until the end of June," Caetano said. "In our conversations with the club so far, they didn't tell us that they were willing to extend the loan."

Martins has made just three first-team appearances for Benfica since joining the club from Ponte Preta in 2014.