The Reds have still to prove their worth as the final months of the season approach, but Redknapp knows the Merseysiders will prove a much tougher proposition this Sunday.
Redknapp said: "Liverpool are one of the top five teams in the country, and we know it is going to be very tough. But we will go there and do our best - it's a great place to play football. We beat them at home in the league a couple of months ago, but they had a few players out that day. They had a slow start to the season. But their results have started to improve recently, and they have some great players all over the pitch.
"Injuries have been a problem this season, and we are going to go to Liverpool with just 17 players to choose from. I strengthened the squad during the transfer window but I have lost Teddy with a torn hamstring - while Lomano LuaLua and John Curtis are both cup-tied. It is like I am back to square one. The league is all important, and the crucial thing for us is that we stay up. But every game is vital, and we want to win and book our place in the next round."