Hargreaves caused a minor sensation last summer when he signed a one-year contract with Manchester City following his release by Manchester United.
Plagued by injury for the previous three seasons, it appeared Hargreaves had won his fitness battle when he made a goalscoring Blues debut against Birmingham in the Carling Cup in September.
However, the 31-year-old made just three more appearances for City and after being released by the club, Hargreaves admitted retirement was one of the options he is thinking about.
He said: "I don't want to chase something. If I get the right fit I will go for it. But I am not forced to do anything and if I can't get back to the level I used to, I don't want to play."
"I am a football player," Hargreaves said. "That is how I am identified as an individual.
"I was pretty humbled in the sense that was taken away from me. Now it is about taking the next step and deciding what I want to do.
"But the really satisfying thing is that I have put myself in a position where I can actually think about it.
"Maybe I will never be in a Champions League final or semi-final again but to get to where I am now is a huge achievement."
Following old team-mate Gary Neville into coaching appeals, and Hargreaves speaks well enough for a career in the media should he so wish.
"No matter what happens from this point forward, I can hold my head up high," he said.
"I wanted to finish on a better note than that Wolves game (where he came off injured minutes into his first-team comeback for Manchester United).
"To have done that would have been awful. I couldn't face that."