Real Madrid left-back Marcelo appears set for a spell on the sidelines after the club confirmed he has sustained an injury to his left leg.
According to Madrid, the Brazil international has a Grade 2 tear of his left bicep femoris muscle, which extends from the hip to the knee.
The club states the injury will be monitored but reports suggest the defender could be out for up to a month.
Marcelo was substituted in the 71st minute of Madrid's shock 1-0 home defeat to Real Betis on Wednesday, having missed the club's previous La Liga match due to a red-card suspension.
"I have pain in my leg. We'll see after scans," Marcelo said after the loss.
Should the injury keep the defender out for near the reported length of time, he would miss the Champions League clash with Borussia Dortmund on September 26 and may be in danger of also missing out on the match against Tottenham on October 17, in addition to La Liga matches against Alaves, Espanyol, Getafe, Eibar and Girona.
A slow start to the La Liga campaign sees Madrid eighth in the table, seven points behind rivals and league leaders Barcelona.