Sheffield Wednesday manager Dave Jones confirmed defender Kamil Zayatte could be sidelined for over two months due to an ankle injury.
Zayatte has been a regular starter for Jones this season since joining on a free transfer in the summer following his departure from Turkish club Istanbul BB, but having missed the weekend defeat to Huddersfield the centre-half is set for a longer-than-expected spell on the sidelines.
Jones, who made three other changes for Saturday's 2-1 home derby defeat - goalkeeper Chris Kirkland, defender Reda Johnson and midfielder Seyi Olofinjana were all left out - said: "Zayatte will be out for eight to 10 weeks with an ankle injury.
"I made changes because we didn't play well in the last game. No manager drops a player for playing well.
"I could have made a lot more changes.
"Why did I leave out Kirky? Because we haven't kept a clean sheet and I didn't think he was playing near to the standard he expects or I would expect from him."
On-loan Arsenal keeper Damian Martinez made his first appearance for the club in place of Kirkland, Miguel Llera stepped in for Zayatte and Joe Mattock was preferred to Reda Johnson.
"Miguel Llera has played enough games to be able to slot in," Jones added. "I thought changing Reda was the right thing, because Joe Mattock has been doing well.
"Joe did okay, Jose Semedo as well. You can't just keep picking the same players that aren't performing week in, week out.
"Seyi had been to Nigeria - he had something to sort out over there. I just felt that the travelling and everything else wasn't right, and Semi has done well and was playing well before he was suspended."