Chelsea boss Mourinho: Most competitive Premiership in recent times
"There are a lot of good teams in the league now," explained Mourinho.
"There is a big improvement in the teams below the top four, so it can be more normal for big teams to lose matches and points this season.
"Other teams have spent money, changed their teams and improved - Villa is just one example, you can find lots of others.
"It's more difficult now to fight against these teams - but the table after five games does not mean much."