Steve Bruce will wait for medical reports on George McCartney before confirming whether the defender will be fit to face Hull this weekend.
McCartney was stretchered off in obvious pain in the second half of the 1-1 draw with Brighton after falling awkwardly on his ankle.
The injury comes as a bitter blow to the Northern Irish international, who has only just returned after beating the niggly back problem which kept him out of the Darlington game.
Michael Liddle and Kieran Richardson will battle for the left-back spot if McCartney is absent, and the defender is set to be examined further by the club's medical team on Thursday.
"We hope it's not too serious," Bruce said. "He's twisted his ankle. We hope it's not too bad.
"We'll have a look. It's a sore one but we'll see how he is."