Zola tried to sign Balotelli in the summer but although that deal failed to materialise he is still keen on the young Italian, who could yet play for Ghana in next summer's World Cup finals.
"If Inter want to talk about him in January we are ready," Zola told Corriere dello Sport.
"Mario has extraordinary potential, but he must understand that he has to improve, showing the right attitude.
"Last summer there was a time when we asked about him. In January, we will see what intention they have.
"And sure if he does leave Milan, we would not be the only ones who want him."