Derby County defender Sondre Langas has been ruled out until the new year after suffering a groin injury in Wednesday's heavy defeat at Queens Park Rangers.
The 25-year-old Norway international limped off the pitch after just 12 minutes when the game was still scoreless.
The Rams were two goals down within 10 minutes of his exit, as they went on to lose the Championship match 4-1.
Langas underwent scans soon after the game before meeting with a surgeon, and is not expected to be back until at least the middle of January - which means he could miss as many as 15 matches.
Losing Langas adds to an already major injury crisis for the Rams, who are without hugely influential defenders Matt Clarke, Craig Forsyth and Eiran Cashin.
Derby boss John Eustace said losing Langas comes as a "big blow" to a side that is in the Championship relegation places.
Langas, who featured at last summer's World Cup for Norway, was ever present for Derby in their opening 11 league and cup games.
"Sonny is a true warrior, he has proven that over the time he has been playing for me," Eustace told BBC Radio Derby.
"He tried to carry on, but unfortunately he couldn't and ended up staying down in London to the surgeon this morning.
"It's a big blow to us, of course it is, but it gives somebody an opportunity to now step in – if there is anyone."