The Sun says the Argentine striker, 28, has just 18 months left on his current deal.
And boss Roberto Mancini indicated last week he would like his former skipper to stay.
But he said: "I've one year left on my deal and City want me to sign for two more seasons. I'll think about it.
"This year is different from last, when I wanted to end the contract with City. I'm happy here as they're treating me well.
"Sometimes I play, sometimes I don't, but that's OK."