The 27-year-old, who has undergone knee surgery, will miss Chelsea's pre-season tour of the United States.
A statement on the club's website said: "In light of his previous surgery, excellent rehab and recent return to full training, this is only a minor setback and we expect Cole to return to full training in approximately one month."
The England midfielder had recently recovered from cruciate ligament
damage sustained in January, an injury that ruled him out of the whole of last season.
Invalid email
We use your sign-up to provide content in ways you've consented to and to improve our understanding of you. This may include adverts from us and 3rd parties based on our understanding. You can unsubscribe at any time. Read our Privacy Policy