The left-back has a muscle injury and will be replaced by Leeds loanee Clarke Oduor for the vital home clash with the Hoops.
Struber said: “It is not so easy. He has problems with the muscle and he is not sure he can play.
"He trained with us and we will see after training. If the risk is too high, then we will start with Clarke.
"He is a big talent and I trust he can create a good performance for us. He is a very, very player.
"The training sessions from him in the last 14 games have been very good. I hope he can bring the training performance in the game. Clarke is a very good player."
The Reds, who drew with Reading on Wednesday having taken the lead, also have a doubt of Aapo Halme, but there are no other fitness concerns.
Struber has had a glut of games since taking over almost a month ago, has started to turn his mind towards January.
The Austrian has hinted he will look to the loan market in a bid to strengthen his squad in the battle to beat the drop.
"Maybe. It's not a fixed (buy) and it is a model we will show in the next time in January,” he said.
“It is a serious system and at the end, it is a win-win for the player, for us and the club.
"I hope that in January that we bring a good decision with the right players to help us."