Riyadh | Cristiano Ronaldo's hamstring injury is more serious than first thought, Al-Nassr coach Jorge Jesus said.

Ronaldo, 41, limped out of Al-Nassr's 3-1 Saudi Pro League victory over Al-Fayha last weekend.

"In the last game, Cristiano left with a muscle injury," Jesus told journalists on Friday.

"After the tests he underwent, it became clear that it is a more serious injury than we were expecting.

"He will need rest and recovery. Cristiano will travel to Spain for treatment, as will other players who were injured. He will need treatment from his personal physiotherapist. We hope he will return soon to help the team." Former Real Madrid star Ronaldo's availability for Portugal's friendlies later this month, as it ramps up preparations for the World Cup, may now be in doubt.

Portugal plays Mexico in Mexico City on March 28 before facing the United States in Atlanta on April 1.

Ronaldo has scored 21 goals in 22 league games this season for Al-Nassr.