The Blues are currently 10 points behind Manchester United, who are at the top of the Premier League.
O’Neill said: “I think Chelsea need to win against us to stay in the title race with Manchester United having won their games in hand, and opened up that five-point gap over Liverpool and another five points on top of that over Chelsea.
“With 13 games left, for Chelsea to stand any chance they will maybe need to win 11 games and be unbeaten in the 13 games.
“That would take some doing but, with that group of players who have been over the same course before, it is not beyond them to achieve that.
“Last season, with about this number of games left it looked as if they were out of the picture and then they had a very good run and only effectively lost the chance when they drew with Wigan who scored very late on.
“That was with only a couple of games left so they pulled it right around and then were within a width of a goalpost of winning the Champions League final.”