There are reports Mario Mandzukic could be out of action for a month, putting the Juventus striker at risk to face Atletico Madrid.
The Croatia international pulled up during training on Thursday and Max Allegri confessed the prospects of a quick recovery were not good.
According to the latest rumours, there are fears he has a lesion in the femoral bicep of his right thigh.
It could be bad enough to require a month on the sidelines and that would be a huge problem for the Bianconeri.
They are set to face Atletico Madrid in the Champions League Round of 16 on February 20.
This injury is another reason why Juventus are refusing to let teenage forward Moise Kean go out on loan in January.
Juan Cuadrado has been ruled out for three months with a meniscus and cartilage injury in his knee.