Sean Dyche revealed that summer signing Ben Gibson is facing another minor operation as the Clarets' defensive resources are stretched.
A 4-2 defeat at West Ham United made it 13 goals conceded in three games.
But former Middlesbrough centre-back Gibson is not yet in a position to challenge for a first-team place and Dyche also confirmed that James Tarkowski requires further attention to the groin problem that has dogged him so far this season.
"Ben is going to have a hernia operation and Tarky is going to see a specialist this week," said Dyche following the Clarets' loss at the London Stadium.