Allardyce lost Ramage and Stephen Carr to injury on Sunday, and he is desperate to bring in another right-back before midnight on Friday.Chelsea right-back Glen Johnson is tipped by the London media to be his main target, while Bolton Wanderers' Abdoulaye Faye could finally complete a move to St James's Park before the deadline.
But Portsmouth, who Johnson had a successful loan spell, are also in for the former West Ham man.
Allardyce: "I was looking to get in one more defender before Friday, but now I'm looking to get another in. And, really, because of the injury situation, I don't feel as though I can let anyone go.
"Stephen Carr has a straight-forward hamstring injury, but it will still keep him out for four to six weeks.
"As far as Peter Ramage is concerned, it's not looking good.
"It could be that he'll need a trip to Richard Steadman's clinic in America."