كتب : Mohamed Sabe
The Brazilian international tore the anterior cruciate ligament in his right knee during Valencia's 3-0 defeat to Sevilla in La Liga on Saturday.
"I knew it was serious when it happened and I felt terrible," Edu told reporters.
It is the second time that the former Arsenal player suffered this sort of injury.
He spent seven months recuperating from a similar damage to his left knee, just after arriving at the Mestalla.
"It's an injury that requires a lot of hard work every day during the recovery period, but I have to be strong and I will do all I can to ensure that I come back," he added.
The 28-year-old will undergo surgery in his native Brazil where he will spend most of his layoff period.