Why big-spending Newcastle have 'surprised' Claudio Ranieri
Ranieri's table-topping Leicester City are the club's next opponents.
Both clubs fought successful battles against relegation from the Premier League last season.
Yet Leicester are now five points clear at the top of the table, while Newcastle are 19th in the division and a point adrift of safety.
United's form is set to cost head coach Steve McClaren his job – the club hopes to appoint Rafa Benitez as his successor – and it is not clear who will be in the dugout at the King Power Stadium on Monday night.
Asked about his team's title hopes, Ranieri said: "Now we are not thinking about how many points.
"We are thinking about Newcastle. It's a difficult match, they are in a dangerous position. They spent more than £100million and I think it will be another difficult match. They are fighting to survive.
"I am very surprised (they are struggling), they have a good manager, good players and fantastic fans."