But Zola is adamant Hazard must top that chart, while admitting he still holds out hope the Belgium playmaker will not depart for Real Madrid this summer.

"Eden Hazard's definitely at the very top," said Zola, ranking the 28-year-old as Chelsea's best-ever overseas signing.

"He's such an unbelievable player. The more I've spent time with him the more I appreciate him as a player, but also as a boy.

"He's been great. I would love to have him for longer. What we are trying to do here perfectly suits him. It's no coincidence that he's having his best season.

"I don't want to take anything away from him and what he has achieved. But certainly the way we play helps him a lot."

Madrid are expected to lure Hazard away from Chelsea this summer, with the Belgium star's current Stamford Bridge deal expiring at the end of next season.

Chelsea continue to hold out for £100million however, with Real boss Zinedine Zidane keen to add the livewire forward to his Bernabeu rebuilding project.

Hazard has 85 goals and 81 assists from his 241 Premier League appearances for Chelsea since his 2012 debut.

Despite continuing to hope the Belgian will stay at Chelsea next term, Zola insisted the Blues can still pull off a strong end to the campaign by winning the Europa League and finishing fourth in the Premier League.

"Of course we hope that Hazard will stay with us because he's such an important player for us," said Zola.

"There's a lot of talking around this team, I realise that.

"But we as coaches have to make sure we are not distracted by all of that.

"We need to maintain focus, because this year a lot of times I heard talk that it's been a bad season.

"But if we can reach the final and maybe win the Europa League and end up fourth in the Premier League, I think it could be a remarkable season."

ga('create', 'UA-72310761-1', 'auto', {'name': 'pacontentapi'});
ga('pacontentapi.set', 'referrer', location.origin);
ga('pacontentapi.set', 'dimension1', 'By Nick Purewal, Press Association Sport');
ga('pacontentapi.set', 'dimension2', '68c2caf7-bb20-4e11-b43c-cc493ed41a3a');
ga('pacontentapi.set', 'dimension3', 'paservice:sport,paservice:sport:uk');
ga('pacontentapi.set', 'dimension6', 'story');
ga('pacontentapi.set', 'dimension7', 'composite');
ga('pacontentapi.set', 'dimension8', null);
ga('pacontentapi.set', 'dimension9', 'sport:football');
ga('pacontentapi.send', 'pageview', { 'location': location.href, 'page': (location.pathname + location.search + location.hash), 'title': 'Zola claims Hazard is Chelsea\u2019s best import'});