The Welsh midfielder, who has already missed 16 matches this season due to fitness issues, will miss Wales' first set of 2022 World Cup qualifying fixtures due to a thigh issue.
Ahead of their Serie A clash with Cagliari, An official statement on Juve's social media accounts said: "Buffon (back pain) and Ramsey (left thigh) are both out of the Cagliari vs Juventus squad."
The Bianconeri’s boss, Andrea Pirlo, told his pre-match press conference about the 30-year-old midfielder: "He has physical problems and is unable to get continuity to his performances because he has to stop every two or three games.
"In the past, he has had major problems that have kept him away from the pitch for months. He is precious because he knows how to make the team play well and he plays well. He has only this physical weakness that forces him to stay out every now and then."
Gianluigi Buffon will also miss the Cagliari Match for a back problem.