Promising Portuguese right-back Nélson Semedo underwent knee surgery in Hospital da Luz (Lisbon) this afternoon announced the club via their official website.

The youngster returned from International duty with an injury following Portugal's win away to Serbia, where he played the full 90 minutes. Benfica informed the player was operated due to an osteochondral fracture on his right knee.

An osteochondral fracture is a break in the surface of a joint that involves the cartilage and underlying bone. The most commonly affected joint is the knee joint. The injury is also most common in adolescent males. Cartilage has a limited blood supply, which makes healing this type of injury difficult.

Nélson will be sidelines until 2016 and will miss key fixtures in the next coming months such as the Lisbon derby on Sunday 25th October and the remaining Champions League group games.

André Almeida, Sílvio and Victor Lindelöf are the likely replacements for Rui Vitória.

In social media, Greek striker and teammate Mitroglou wished the player a speed recovery.

Former youth teammate Fábio Cardoso: