Heskey said: "I think Birmingham is a progressive and ambitious club and very much going in the right direction. But they are also building within a sensible framework without throwing money around and jeopardising the future of the club.
"I am keen to play as an out-and-out striker, which I haven't done since my second season at Liverpool, and Steve has made it clear that is the role that he sees for me.
"I am also looking forward to linking up with Mikael Forssell. I have been very impressed with what I have seen of him and I think we can create an effective partnership."