Ashley Barnes is likely to be out for around a month after he undergoes hernia surgery on Friday.
The six-goal striker has been managing a troublesome groin injury, having been rested at Spurs and Everton in December.
But he has missed the last two games – the FA Cup win over Peterborough United and Premier League defeat at Chelsea.
And after seeing a specialist last Friday, the club got a second opinion on Monday, and he will have an operation on Friday.
Boss Sean Dyche explained: “He’s been trying to get through it, but it’s been affecting him, and after seeing the specialist, it was decided he needed a hernia operation.
“He’ll have that on Friday, and hopefully it will be straightforward, as they seem to think it will be.
“Generally speaking, if it is pretty straightforward, it should be a pretty quick turnaround nowadays.
“He should be walking in days, and jogging after a few more days.”
Ben Gibson, who required a second operation, and James Tarkowski were out for a month at a time after hernia surgery last season.
That leaves Dyche down to three senior strikers for the forseeable future, in Chris Wood, Jay Rodriguez – who has shrugged off the illness which saw him miss the trip to Stamford Bridge – and Matej Vydra.