The Bosnia goalkeeper is struggling with a thigh problem and Hughes has put Thomas Sorensen, who has not started a league game since May 2012, on standby to replace him.
Speaking on the club's website on Thursday, Hughes said: "Asmir is the big worry for us at the moment because of a knock to his thigh on Tuesday.
"He has a bit of bleeding in there, so we need to nurse him and then assess him tomorrow to see where he is at.
"It is a bit of a concern as he has been outstanding for us this year, but we will see what happens over the course of the next 24 hours."
Sorensen has featured mainly in domestic cup ties over the past two seasons but Hughes has no doubts about the 37-year-old Dane's ability to step in at short notice.
"If Asmir isn't ready then I will have no qualms in throwing Thomas into the team," he said.
"He is a top keeper in his own right who has an abundance of experience behind him."