The Wanderers boss is keen to add another stopper to the ranks who will provide competition for both Jussi Jaaskelainen and Kevin Poole but is wary that he could hit a brick wall as there aren't too many keepers available at the moment.
Other than Jaaskelainen and Poole the club have to look to youngsters Sam Ashton and Chris Howarth for goalkeeping cover and Allardyce says this is not an ideal situation to be in.
"I'm still looking and working away," Allardyce told the official website
"Certainly from the goalkeeper point of view, that is an absolute necessity. We're riding with only Jussi and Kevin Poole and our next goalie is 18 years old and in the Academy so we do need to secure that position before Tuesday. Quite where or how is still difficult to say. They are always as hard to find as goalscorers but we're still plugging away and hopefully can come up with the right one before the deadline" he added