The France international was an unused substitute at the weekend as the Spanish side beat Eibar, resting him ahead of the quarter-final first leg.
He is a key component in Zinedine Zidane’s team and will be a big loss for the reigning champions of LaLiga - and even more so as they are still without his usual partner in defence, and club captain, Sergio Ramos.
A short club statement noted that Varane had taken the test on Tuesday morning ahead of the clash with the Reds, which takes place at the Estadio Alfredo Di Stefano at 8pm.
Real are also without right-back Dani Carvajal and forward Eden Hazard through injury, though midfielder Fede Valverde has recovered to be in the squad.
The 27-year-old’s absence will mean Zidane has to decide on something of a patchwork defence, which will likely see Eder Militao and Nacho partner up in the centre. They could be joined in a back three by Ferland Mendy, who might also play left-back in a four-man line-up.
Liverpool have had their own issues to contend with at the back this season, with long-term injuries to Virgil van Dijk, Joe Gomez and Joel Matip meaning that neither side will have any of their first-choice centre-backs on show for the first leg.
Jurgen Klopp’s side have returned to form of late with three straight wins in all competitions, with Ozan Kabak and Nat Phillips the new partnership at the back.
Real have won four in a row themselves, with Varane a fixture in the previous three before the weekend victory.
The second leg takes place at Anfield next week and the winners of the tie will face Chelsea or Porto in the semi-finals.