Charles' condition was said to be no longer critical following the operation to repair an aortic aneurysm in Milan's San Carlo hospital on Tuesday night.
He was due to have appeared as a guest on La Domenica Sportiva, a popular sports show on Italian television that evening.
Dr Piergiorgio Settembrini, the surgeon who operated on Charles, said: "The patient is recovering well. He's on the right road to recovery even if we have to remain cautious up to 72 hours after surgery.
"I had a chat with him this morning, and he asked me about the Serie A football results, which shows that he is in good spirits. He is strong and he can resist the pain well."