Boro hung onto the 20th-minute lead given to them by Turkish striker Tuncay Sanli after a slip by David James and Redknapp said: "I won't make excuses. It was a bad performance. It looked like a horrible game to me.
"Some of the players looked very tired. I gave Sulley Muntari a rest because he's done excellent and we play Reading on Tuesday and have a few injuries.
"I expected to beat Middlesbrough but we never really got going and in the end were just lumping balls onto the heads of Huth and Woodgate in the Boro defence.
"We were 11 games unbeaten until a couple of weeks ago and got a good point against Arsenal in the week. This is a second 1-0 defeat at home and we didn't do great against Spurs, but it's about players not systems.
"I don't know where the next goal is coming from here for us but we just keep battling on. We are going to have to do that because when we lose four players to the African Cup next month we'll be down to a bare 14 in the squad.
"We need to get some bodies in, maybe a few loans, but nobody is going to give you proven goalscorers. Benjani has done well to get nine - that's more than he's ever got in his life in one season but now he's struggling too."