Press Association Sport understands Luiz's Instagram post, which was annotated with a needle and the words 'Let's do it' and 'Hahahah', was taken during the ongoing management of a knee injury.
The pain stems from a tackle from Sergio Aguero in December which saw the Manchester City striker sent off.
The Brazil defender was on Friday described as "a warrior" by head coach Antonio Conte for playing with the lingering aggravation.
"He's playing with this little pain in his knee
But he's a warrior," Conte said.
Premier League leaders Chelsea next play at Wolves in the FA Cup fifth round on Saturday.
John Terry last week posted an Instagram video of his ankle receiving stitches to a wound.
Kurt Zouma and Nathan Ake are other defensive options who could come in for the tie at Molineux.
Source : PA