He had targeted a deal for Demel, but the Ivory Coast international has opted to stay at Hamburg until the end of the season.
That has prompted Bruce to now train his sights on Beye, who has made just nine appearances for Villa since his move from Newcastle United last summer.
The Black Cats boss is now waiting to learn whether Villa will be prepared to let Beye return to the North East before the end of the money.
"It's defensively that we are looking to do things this month," said Bruce.
"I went to bat with only two full-backs, (George) McCartney who is sick this weekend and (Phil) Bardsley. It gives me problems whenever there is a slight injury.
"We are still looking to sign players at the back, it's the area we are short. We are down to the bare bones in that respect so that's where we are trying to reinforce and strengthen.
"Habib Beye is one I like and admire, but that's as a far as it has gone at the moment.
"We are interested in him and we have had a look at him, but I'm not sure whether we are going to be able to do anything."
Portsmouth 6/4, Sunderland 7/4, Draw 12/5