Warburton has today (Tuesday) seen a specialist and will now start his rehabilitation as he aims for a return around the New Year.
John Miles, Head of Medical Services at Cardiff Blues, said: “Sam has suffered a grade two strain to his right ankle and has now seen the specialist to start his recovery process.
“He will return to the specialist in a week’s time for further assessment and currently we are working at a minimum lay-off of four weeks for a return to play.”
Head Coach Danny Wilson added: “We are hoping it is a four-week lay-off and Sam is a great professional who will work hard to get himself back as quick as possible. We wish him well with his recovery.”