Pompey will be hit by the departures of John Utaka, Papa Bouba Diop, Sulley Muntari, Lauren and Kanu next week and Redknapp will be short on numbers.
He said: "When they go away we will have exactly 14 outfield players. There are no spares about anywhere.
"We had 20 but Linvoy Primus and Martin Cranie are both long-term injured so when four go that leaves me with just 14 and we won't be able to get through that period with just that.
"I have to get a couple from somewhere. I am looking for a couple of loans or, if we can find them, a couple of frees.
"I know where there are one or two players who would do a good job for us if we could get them."