Robbie Brady is to undergo knee surgery and faces a ‘substantial’ time out of action.
Brady injured his left knee during the Clarets’ 1-0 defeat at Leicester City last Saturday.
He has since been under medical assessment, with manager Sean Dyche confirming the winger sustained damage to his patellar tendon.
Dyche said: “Robbie will have surgery to repair a patellar tendon tear and will be out for a substantial recovery period.
“He will be given all the time and care he needs on his recovery and supported throughout from all of us at Burnley Football Club.”
Brady, 25, joined the Clarets from Norwich City last January as the club’s then-record signing.
The Republic of Ireland international has since made 31 Burnley appearances and had been an ever-present in the Premier League so far this season.
His outstanding run of form has helped the Clarets make a best start to a top-flight season since 1973/74, with Dyche’s side currently sitting seventh in the table.
Brady’s first league goal of the season at Bournemouth a week ago secured a fourth away victory of the campaign – the highest number of away wins at the top level by a Burnley side since 1974/75.