The Portuguese boss returns to Stamford Bridge on Saturday as his Manchester United side take on Maurizio Sarri’s in-form Blues.
Chelsea are still unbeaten and sit atop the table alongside Manchester City and Liverpool, chiefly thanks to their Belgian superstar.
Mourinho worked with Hazard in his second managerial stint at The Bridge and believes that, should the forward stay fit, the West London club have a great of sealing it once more.
The United manager said: “The results speak for themselves.
“Obviously they are not playing in the Champions League.
“That puts them just in the Premier League, and in the Premier League the results speak for themselves.
“Very good results, top of the league and of course lots of good players.
“History says that when Eden Hazard is the best player in the Premier League, Chelsea are the champions.
“It happened with me and Antonio [Conte] and this season – it is still the beginning of course.
“But if he is the best player in the Premier League until now, which he is, Chelsea is top of the league because he is the kind of player who can make a huge difference.”
Hazard revealed earlier in the week he would enjoy playing for Mourinho again.
But while the United boss would be delighted to have him, he knows there is no chance would ever sell to one of their biggest rivals.
“I would love to have him at United but I don’t think Chelsea will sell him,” he said.
“Chelsea is led by intelligent and experienced people and they would never sell Eden to Manchester United.
“He is a nice kid. We had a good relationship. We were champions together.
“He was for the first time the best player in the league with me, so I think the feelings are good.”
Mourinho has asked for more time before responding to his FA charge of using foul and abusive language following United’s 3-2 win over Newcastle before the international break.
Mourinho is alleged to have sworn at TV cameras in his native Portuguese and had until 6pm last night to respond.
But United have asked for more time before officially responding and FA bosses have given Mourinho a new deadline of 6pm on Wednesday.
It means he will be on the touchline at Stamford Bridge today, where Chelsea may have to do without England midfielder Ross Barkley, who picked up a knock in the Nations League win against Spain this week.
