Real Madrid announced that English right-back Trent Alexander-Arnold suffered a hamstring injury during the capital club's 2-1 win over Marseille in the Champions League.
The former Liverpool star played just four minutes of Tuesday's 2-1 win against the French side, as the 15-time European champions opened their European campaign with a hard-fought victory.
Los Blancos still managed to secure a positive result despite playing with 10 men after Dani Carvajal, who replaced Alexander-Arnold, was sent off in the 72nd minute.
"Following tests carried out today on our player Trent Alexander-Arnold by the Real Madrid medical team, he has been diagnosed with a hamstring injury in his left leg," the club said in a statement on Wednesday.
Local media reports that Alexander-Arnold will be out for around three weeks.
The 25-year-old was brought in by Real Madrid in the summer transfer window to provide competition for Carvajal, who suffered a long-term injury last season.
Now, both right-backs are confirmed to miss Real Madrid's second Champions League match against Kazakhstan club Kairat Almaty on September 30.
