The Spanish giants stated that the Brazilian is now considered a significant doubt to face the Premier League leaders on Wednesday evening.
A club statement read: "Following tests carried out today by the Real Madrid Medical Services on our player Vini Jr., he has been diagnosed with an injury to the biceps femoris in his left leg. His progress will be monitored."
Los Blancos are due to fly to England to face a Liverpool side who are in fantastic form at the moment.
Rodrygo, Aurelien Tchouameni and Lucas Vazquez are all pushing to be available after injury, however, which means Madrid could be well equipped to replace the 24 year old.
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