The Black Cats, like clubs around the country, will forego part of the festivities as they prepare for their Boxing Day clash with Barclays Premier League champions Manchester City.
However, 60-year-old O'Neill insists that is a small price to pay for the life modern-day players lead.
He said: "It's the most phenomenal life you could get, particularly if you have a couple of years where you can be successful.
"I was lucky enough to be involved in a Nottingham Forest team which ruled Europe for a couple of years, so that was really fantastic.
"But any professional player has got to really enjoy it. You are being paid to keep yourself healthy and fit and if you don't have any major serious injuries, which are obviously more than a bit of a setback and terrible to endure, then it's a great career."
O'Neill added with a smile: "Any of those players who fancy going into management, I give them one piece of advice: forget about it."
- Sports & Recreation
- Barclays Premier League