The Black Cats have now lost four of their last five league matches and are in danger of being sucked into a relegation battle, which Redknapp believes requires 37 points to avoid.
"We have 30 on the board," O'Neill said. "He was speaking from a position of having 20, so you have to try and win those games.
"His team needed 17 from the last 10. That is European form. We need to start winning, really. I think next week is a big, big game for us.
"We have difficult fixtures coming up, including Norwich. We have our work cut out. We have known that since the start of the season.
"It has been tough going throughout the season and we have to fight through these last nine games.
"I was asked about being close to 10th and close to being relegated yesterday. It will be like that until the end of the season."