Riad suffered the injury during Gouna's goalless draw with Zamalek on Thursday.

The 27-year-old, who came on as a second-half substitute, was stretchered off ten minutes from time after tangling with Zamalek midfielder Ahmed Al-Merghani.

"He will probably fly to Switzerland to undergo treatment," Gouna football director Ahmed Al-Seheifi told FilGoal.com on Saturday.

The news will come as a blow to coach Ismail Youssef, who was expected to rely heavily on Riad as he bids to at least keep the newly-promoted Gouna among the elites.

The diminutive midfielder, who joined Gouna in the close season after his former club Telecom Egypt were relegated to the second division, was one of several big-name signings for the privately-owned club.

They also landed Feyenoord goalkeeper Sherif Ekrami and former Ahli duo Amr Samaka and Hussein Ali.