Redknapp has confirmed talks with Manchester City over a deal for the Togo striker.
Redknapp said: "When he was at Arsenal he was almost unplayable and if he comes here that's what we are looking for him to do. There's no reason he can't do that.
"He was fantastic against us in Madrid last year. We couldn't handle him and if he's at it and he comes here and really wants to play, then he could be sensational.
"I stuck up for him when he scored that game (against Arsenal).
"They had been abusing him all game and when he scored, what was he supposed to do? You stick it up them don't you and that's what he did.
"He rang me and said that he appreciated it. I'm sure I'll get on with him if he comes here."