Chelsea star Hazard heaps praise on Tottenham's Belgian duo
He said: "Dembele is a big player; I think he is one of the best players in the league at this time and it is difficult to defend against him.
"He has great pace and good technique, and is very effective in the centre of the pitch.
"I follow all the Belgian players in the Premier League, and now he is at a bigger club with better players it will be good for him."
The Blues ace added: "Normally Vertonghen is a central defender and not a left-back but he can play both. He is very good technically and likes to bring the ball forward out of defence."