With James Collins, Joey O'Brien (both hamstring) and George McCartney (knee) injured and a Barclays Premier League home clash with QPR to come for his team on Saturday, Allardyce admits he is looking for reinforcements.
The 58-year-old, who is interested in Blackburn full-back Martin Olsson, said: "We will try to get some defenders in as quick as we can."
Allardyce fielded an experimental back-line in Wednesday night's FA Cup third-round replay at Manchester United. Opting to rest Guy Demel by leaving him on the bench, the manager brought midfielder Alou Diarra into a central defensive trio alongside Winston Reid and James Tomkins, with Jordan Spence and Daniel Potts operating as wing-backs.
"Alou Diarra did a fantastic job to help on our defensive side, because in terms of player availability, we only had Winston Reid, James Tomkins and Guy Demel who were experienced defenders," he said.
"Alou Diarra stepped into the middle of the back three and did very well.
"Young Jordan Spence and Danny Potts were playing as wing-backs and they did well.
"But we want to improve the squad and we want to get our injured players back as soon as we possibly can."
- Sports & Recreation
- Alou Diarra
- Martin Olsson