That's bad news but the worst news of all is that in six to eight weeks he faces further surgery. The worst fears were always that he could have damage to his cruciate ligament and it has now been confirmed that he has snapped that as well.
Duff will now join Bes Berisha in facing a long road towards fitness, and as is the case with Berisha he won't feature for the Clarets again this season. Steve Cotterill had already spoken about the possibility of strengthening his squad and this news will make that more likely.
We can only wish Duff a speedy recovery and look forward to seeing him back in a claret and blue shirt next season.