Al-Nassr's press service announced on its X social media page that 41-year-old striker and team captain Cristiano Ronaldo has been injured.
"Cristiano Ronaldo was diagnosed with a thigh muscle injury after the last game against Al-Feiha. He has started a rehabilitation program and will be monitored daily," the club said in a statement.
Earlier, media reported that Ronaldo had left Saudi Arabia due to military operations in the region.
Al-Nassr won 3-1 against Al-Feiha in the 24th round of the Saudi Pro League. Ronaldo was on the field for 81 minutes of the match. The Portuguese forward missed a penalty in the 11th minute.
In total, Ronaldo has scored 21 goals in 22 Pro League games this season.