The Spurs boss saw his team beaten 2-0 by the Foxes and lamented the poor performances and individual errors made by his side.
Mourinho told Sky Sports: "We didn't start well. I could go on the individuals but I don't.
"But in our best period in the first half when we were totally in control and had a couple of good chances to score, expecting to go in 0-0 you go with 1-0 down.
"Then in the second half we score in our own goal when we had possession and we were in more creation. That was difficult. The reaction was positive.
"Our performance was not good but it was not like they deserved to win, or we deserved to lose. It was a poor game."
Tottenham have now fallen to fifth in the league table and Mourinho confessed that it had been a bad week for his side after the midweek loss to Liverpool.
He said: "It's not a good week in terms of results. We could be here as the ones that broke Liverpool's record at Anfield and go into this game from the high of this level of confidence and happiness.
"I have to admit we started this game from the low of that disappointment of not getting what you deserve in that match but Leicester also lost in the past match and they came with a positive attitude which we didn't start with. And then after that it was a game which could go in both directions. It was a game we lose with a penalty and own goal."