Lukaku spent three years at Chelsea – where he failed to score a single goal for the Blues – but enjoyed two successful loan spells at West Brom and Everton before his permanent move to Goodison Park in 2014.
He's scored 87 goals during his time at Everton, becoming the club's all-time leading scorer in the Premier League in the process.
The 24-year-old has been heavily linked with a move back to Chelsea this summer after turning down a new deal at Everton in search of Champions League football elsewhere.
Chelsea forward Hazard is a big fan of his Belgian compatriot, but has stopped short of convincing Lukaku to join him at Stamford Bridge.
Romelu Lukaku has been linked with a return to Chelsea How Chelsea could look with Romelu Lukaku Tue, March 14, 2017
How could Antonio Conte's Chelsea side look if they signed Everton ace Romelu Lukaku?
Play slideshow Getty 1 of 12
How could Chelsea look if they signed Romelu Lukaku?
Eden Hazard talks potential Romelu Lukaku to Chelsea move
On the prospect of linking up with Lukaku at Chelsea, Hazard told Singapore outlet The Strait Times.: "He's a great player, a great guy and a good friend but he will have to make his own choice.
"He's still young, only 24 but every season he has scored a lot of goals in the Premier League and this shows he's a good striker because the Premier League is very tough.
"But it's not my job to say we need him. The owner and manager are there to buy players. We will see."
Romelu Lukaku could link up with Eden Hazard again at Chelsea
Get Quotes on Home Insurance
According to Lukaku's agent Mino Raiola, Everton will demand a world-record £100million fee for a player they signed for £28m three years ago.
"In two years' time maybe £100million for a guy who makes (scores) 26 goals is a good deal," Raiola told talkSPORT.
"The market will be ruled by the people who buy so if there is a club that needs Lukaku and thinks he is worth £100m, then Everton are right (to ask for that fee)."