Real Madrid defender Eder Militao is facing a period on the sidelines with the hamstring injury that he suffered during Sunday's La Liga contest with Celta Vigo.
The Brazil international picked up the problem during a recovery run, and he was unable to put any weight on his right leg in the aftermath of the incident.
Militao was replaced by Antonio Rudiger in the 24th minute of the match, and it proved to be a very disappointing night for Los Blancos, who suffered a 2-0 home defeat to Celta.
Real Madrid head coach Xabi Alonso admitted that Militao's injury was unsettling for Los Blancos and a major contributor to his side suffering a two-goal reverse.
"From the start, Militao's injury hurt us. It took us a while to recover mentally. Then we made some adjustments, but it wasn't the match we wanted," Alonso told reporters.
Militao suffered a hamstring injury in Real Madrid defeat
“We're at a point where injuries are piling up. Today we had to change things in our game plan with Militao injured.
"We need to be able to maintain continuity, but the team wants to compete and build a foundation, regardless of whether things are going well or not so well. We're on the right track to achieving that.”
According to AS, Real Madrid are 'very worried' about the injury, and there are fears that the Brazilian could now be out of action for a significant amount of time.
Militao will undergo a scan over the next 24 hours to determine the extent of the problem, and a timeline will then emerge once the seriousness of the damage is shown.
A Grade one hamstring injury could see Militao back on the field in a couple of weeks, but a grade two would bring a recovery time of between three to six weeks.
A grade three, meanwhile, could see the centre-back be out for around eight weeks, which would be a major blow for a Real Madrid team that are currently struggling for results.
Militao adds to Real Madrid's defensive injury crisis
Dani Carvajal (knee), Trent Alexander-Arnold (thigh), Dean Huijsen (knee), David Alaba (muscle) and Ferland Mendy (hamstring) are also currently on the sidelines.
As a result, Alonso is set to have only four first-team defenders available for Wednesday's Champions League game against Manchester City - Raul Asencio, Rudiger, Alvaro Carreras and Fran Garcia.
However, Carreras and Garcia will both be suspended for the La Liga game against Alaves next weekend following red cards in the home reverse to Celta.