Redknapp said: "These are great times for Portsmouth. Eleven games unbeaten in the Premier League is a fantastic run, and six successive away wins takes some doing.
"But I would think the top four are on another level really. They've got the squads and are strong. I am not crying, but we will go down to 14 outfield players when the African Nations Cup comes along.
"I haven't got any 19-20 year olds who can come into the plans and play league football. We haven't got any other players, so it is going to be a big problem for us.
"I am going to have to try and find some loan signings from somewhere, but the ones we are losing are big players to lose for five or six games.
"One thing is also guaranteed - the countries they play for will go all the way in the Nations Cup. Ghana, Nigeria and Senegal are three of the strong teams.
"That is where we are going to have problems. We haven't got the back-up at the moment."