The 24-year-old spent most of last season on the sidelines and hobbled out of Saturday's season opener against Watford.
Clarets boss Eddie Howe told the Lancashire Telegraph: "We just want to get him fit and we'll do whatever it takes.
"If that means sending him abroad for treatment, whatever it may be, whether we look abroad for alternatives methods of treatment now.
"There are things out there, there are people abroad - in Germany - who come highly recommended and are specialists in this type of injury," he added.
Burnley won their Carling Cup first-round tie last night, defeating Burton Albion 6-3 after extra time.