The Blues have only won two of the last nine league games and are currently floundering in sixteenth place, just two above the relegation zone.
And Mourinho believes his players’ usual swagger has deserted them, filling any visitors to Stamford Bridge with a new-found winning belief.
He said: “I don’t think fear factor is the right words. Lack of confidence. A little bit less self-esteem.
“That can affect your style of play, your body language in a game. Fear factor? I don’t believe so at this level.”
However he did admit that teams definitely no longer fear the Blues, and given recent results in south-west London, he can see why the visitors are filled with confidence.
He added: “Maybe. It’s normal. One thing is to go to a stadium where you know there’s a huge percentage of defeats for the away team, and another where you go knowing they’ve won only once in four matches.
“So it’s normal that confidence levels and belief in getting a good result are higher for visiting teams. I believe teams come to Stamford Bridge not fearing us and believing they can get a result.”
Chelsea entertain fellow strugglers Aston Villa this Saturday (3.00pm) and will be looking to kick on following the international break.