Eden Hazard can become the best player in the world if he can adapt a few things says Maurizio Sarri

Maurizio Sarri admits he feared Eden Hazard was going to quit Chelsea this summer.

With the Belgium superstar being courted by Real Madrid, new Blues boss Sarri thought he might not get the chance to work with the talisman.

Sarri had to wait until Hazard, 27, returned from the World Cup to talk to him, but ­insists his biggest star is going nowhere, even though the Spanish transfer window remains open.

The ex-Napoli manager says Hazard – who could return to Chelsea’s starting line-up today – can become the best player in the world.

He said: “Chelsea – one of the most ­important clubs in Europe ­– cannot sell an ­important player, without the possibility of buying one on the same level. Of course, I was concerned about this ­problem.

“But after the first time I spoke to him, I was sure he would stay. So I was concerned for 20 days, no more. Now I am sure Eden will be with us for the season.

“We are talking about one of the most ­important players in ­Europe now but, in my opinion, he can improve more.

“He can be the first. It depends on him. The best for technical skill, the best for scoring, but I think it depends only on him. On his mind.

“It depends on his position on the pitch. In the last five years, Cristiano Ronaldo has played like a striker. Lionel Messi like a striker, Eden sometimes like a winger. Eden can improve.

“The World Cup players are working with me very well, more than with the others. They are not completely ready to play 90 minutes. But against Arsenal, we can see one or two in the first part of the match, and one or two in the last part.

“Hazard, technically, is really one of the best in Europe in this ­moment. He has to work from the physical point of view, of course.”

This is the battle of the new London managers trying to get back into the Champions League places and Sarri says ­ Unai Emery can return the ­Gunners to the top four.

Sarri added: “Emery is a very good coach. I think Arsenal, this season, will be competitive.

“They will be able to fight for a place in the Champions League.

“This coach has the ability to start a new era.”