​​Chelsea manager Maurizio Sarri has asked his star forward Eden Hazard to work harder on the training ground as that is only way he will be able to reach the level of Cristiano Ronaldo and Lionel Messi.

Sarri has recently been praising the Belgian forward, especially after his performances for the Blues in the season so far.

The Italian has suggested that while Hazard is close to the level of Ronaldo and Messi, he will need to train harder to attain their levels.

"I think that he's for sure one of the best, but I am absolutely convinced that he can improve," he told a news conference, according to ​Goal.

"If he is able to improve during training maybe he will be able to use himself at 100 per cent because I think that we have seen only 70, 75, 80 per cent of his potential. I think that if he can improve he can be the best in the world."

"For example, [he can do it] with more intensity in training. It's difficult to compare him with others, he's a genius I think, it's very difficult. He is unique," the Italian added.

"I think he has the opportunity to do more. He can be the best player in the world, he's a genius. I want him to be the best in the world," said the former Napoli coach, before signing off.

It remains to be seen if Eden Hazard can keep up his form and help Chelsea win some silverware this season, especially as the club are looking to get back into the top four and challenge for the title as well.