Real Madrid have confirmed that Lucas Vazquez suffered an ankle injury during Wednesday's Spanish Super Cup semi-final with Valencia.
The 31-year-old made his 15th appearance of the season in the team's last match, but he was replaced in the 68th minute of the contest after suffering a sprained ankle.
"Following tests carried out on Lucas Vazquez by the Real Madrid Medical Team, he has been diagnosed with a sprain of the tibioperoneal syndesmosis of the right ankle. His progress will be monitored," read a statement from the Spanish club's official website.
According to journalist Jorge Picon, Vazquez is expected to be on the sidelines for the next six weeks, which will keep him out for the first leg of the last-16 Champions League clash with Liverpool.
Alvaro Odriozola has also had his injury problems this season, meaning that Real Madrid will be relying on Dani Carvajal to stay fit to avoid an issue at right-back.
Vazquez has featured on 10 occasions in La Liga this season, while he also played in three of Real Madrid's six matches in the group stage of the Champions League.
The Spaniard has been consistently linked with a move away from Los Blancos during his time at the club, and he has now entered the final 18 months of his deal in the Spanish capital.
Vazquez's ability to play as a right-back or a right winger makes him an important squad player for Carlo Ancelotti's side, though, and he could therefore sign an extension to his current deal.
Real Madrid are already missing Aurelien Tchouameni and David Alaba, with neither player making the trip to Saudi Arabia for the Spanish Super Cup due to calf problems.
Ancelotti's side beat Valencia on penalties in the competition's first semi-final on Wednesday, and they will take on Barcelona in the final on Sunday.
Eduardo Camavinga and Eder Militao were also both forced off against Valencia, but the pair could be available on Sunday, as they trained alongside their teammates on Friday.
Real Madrid attacker Rodrygo has said that the rest of the squad "are all very well physically" despite being forced to play extra-time against Los Che.
"We are happy to play once again another final of the Spanish Super Cup. We want the game to come now. We have all possible care with physiotherapists, doctors and physical trainers. We have played overtime, but we are all very well physically," he told reporters.
"We always have to be very focused and take advantage of the spaces. We have to be ready for everything that can happen in the game and win. Last year was a springboard for us. After winning, it gave us a great confidence to continue throughout the season.
"We hope that the same thing happens now, that we can win this title and continue very well in everything that remains of the season."
Real Madrid will be back in domestic action next week, facing Villarreal in the last-16 stage of the Copa del Rey before travelling to Athletic Bilbao in La Liga. body check tags ::
