De Bruyne has been absent since suffering a hamstring injury on the opening day of the campaign.
Guardiola said: "If he said he'd be back in January, then it's January. I would like him to play throughout the whole season.
"If he says this, then the New Year will be truly happy for everyone. I don't think such a long break will do him any good. He is no longer 21 years old. Unfortunately, his time is running out.
"He is injured and must recover well and prepare well. We don't expect that a week after rehabilitation he will be fully ready."