The experienced centre-back was stretchered off in his side's 2-1 defeat to Stoke on Wednesday and announced on Instagram and Twitter that he is now facing "an extended spell on the sidelines".
The 33-year-old joined Derby from Hull back in 2017, but has appeared just three times for the 'Rams' this season due to a series of injuries.
"Absolutely gutted to be set for an extended spell on the sidelines," Davies wrote on social media.
"I've been here before and I'm ready to put in the work to come back stronger. I'll see the specialist tomorrow to determine the severity of the injury and the potential length of time I'll be out."
Davies has a wealth of experience in English football's top two divisions, having turned out for West Brom, Aston Villa and Birmingham.
November 29, 2018