Blackburn captain Ryan Nelsen has been ruled out for up to a month after he suffered a hamstring injury in the UEFA Cup defeat by Larissa.
The 29-year-old limped off just before the hour during the 2-0 first round first leg-defeat by the Greek Cup winners at the Panthessaliko Stadium in Volos.
Manager Mark Hughes confirmed the New Zealand player would be out for up to a month after sustaining a hamstring injury.
Hughes told the club's official website: 'It is the operation that he had the operation on but we think it is a bit of scar tissue that has released itself.
'So long term he will be better for that, we hope it is not serious, but he is certainly going to be out in the short term, about three to four weeks.'