Alex Neil admitted news Sean Maguire would be out for three or four months with a hamstring problem was "devastating" for Preston North End.
The Irishman will need surgery on the injury, the latest of a mounting crisis for the Lilywhites.
Maguire's problem is similar to that of Greg Cunningham, the left back's muscle having come away from the tendon against Derby back in August.
Things went from bad to worse in the 3-0 defeat at Ipswich on Saturday as Darnell Fisher also limped off with a groin problem to make it seven defenders on the sidelines.
"Sean's injury is devastating for us," Neil said.
"He has the same injury as Greg Cunningham which means he requires surgery and will be out for the best part of three to four months.
"Apart from Darnell today, none them are soft tissue injuries.
"It is not as if they are over-trained or doing too much.
"They are contact injuries requiring surgery, injuries you can't do anything about.
"We won't sit here and feel sorry for ourselves."
Neil does however hope to have Calum Woods and Josh Earl back after the international break, their medial knee ligament injuries not as bad as first feared.
"They are both grade one injuries, fingers crossed they might be in contention for Bolton," he said.
"But that is best case scenario."