Could Romelu Lukaku be on his way to Chelsea?

With Romelu Lukaku set for a big-money return to Chelsea, we look at whether the Everton striker is ready to lead the line for the Premier League champions.

Romelu Lukaku has never been short of confidence in his own ability. But then, what would you expect from a player who has been scoring goals freely at the top level since he was 16 years old?

The Belgian won the golden boot in his home country in his first full season as a pro, finding the net 15 times as Anderlecht won the title in 2009/10 and scoring four times in Champions League qualifying.

While most players his age were still making their way in youth football, Lukaku had 33 goals in just 73 league appearances for Anderlecht when Chelsea paid £10m to sign him in August 2011.

After a season in the Blues' reserves, Lukaku showed off his goal-scoring ability in the Premier League, hitting the net 17 times during a loan spell with West Bromwich Albion before improving his strike rate at Everton, where he scored 15 goals in 31 games to take Roberto Martinez's side to a fifth-place finish.

Barely 21, Lukaku's stunning start to his football career had made him one of the hottest young talents in Europe. He believed he was ready for the next step. For more responsibility at Chelsea.

But Jose Mourinho, who had seen the striker miss a decisive penalty in the Super Cup defeat to Bayern Munich in the summer of 2013, wasn't convinced. With Diego Costa signed and Didier Drogba returning, Lukaku was down the pecking order.

"He wanted to play for Chelsea but he clearly wanted to be first-choice striker," the manager said at the time. "For a club of our dimension it is very difficult to promise to a player." Everton seized the opportunity, spending a club record £28m to bring Lukaku to Goodison Park on a permanent basis.

Upon Lukaku's arrival, boss Roberto Martinez declared the signing as "a big moment in Everton's history". It was the reception Lukaku wanted and, over the past three seasons, he's revelled in his leading role.

Lukaku has been the club's top scorer every year he's been there, has twice broken the record for goals scored by an Everton player in a Premier League season, and become the Toffees' top scorer in the Premier League era.

Lukaku joined Robbie Fowler, Michael Owen and Wayne Rooney in an elite group of players to have scored over 80 Premier League goals before their 24th birthday, while only Tottenham's Harry Kane outscored in him in the top flight in 2016/17. It's no wonder Chelsea are eager to get him back.

But, with Costa seemingly on his way out, is Lukaku really ready to lead the line for the Premier League champions, as they aim to defend their title and target Champions League glory? There are still some questions marks.

Lukaku will point to his stats from the season just gone. He outscored Costa, as he did in 2015/16, took a greater proportion of his clear-cut chances, and created opportunities for his team-mates more frequently.

But his record of one goal every 622 minutes against the Premier League's top six sides is a recurring criticism, while there are doubts about whether Lukaku can fit into the intense style Antonio Conte has cultivated at Chelsea.

Romelu Lukaku talks with Jamie Carragher about how he's mastered the art of scoring when one-on-one Romelu Lukaku talks with Jamie Carragher about how he's mastered the art of scoring when one-on-one

Lukaku's running numbers don't make impressive reading. No striker to have played more than 1000 minutes last season averaged less than his 8.84km per game, while his 44.77 sprints per match put him 42nd out of 48 forwards.

Costa's average distance covered placed him in the lower third of those standings, too - but he averaged 18 more sprints per game than Lukaku, for the 14th best figure among those regular forwards.

Lukaku & Costa running stats v Premier League 2016/17 forwards (min 1,000 mins) Distance covered/game Sprints/game Romelu Lukaku 8.84km (rank: 48/48) 44.77 (rank: 42/48) Diego Costa 9.75km (rank: 35/48) 62.73 (rank: 14/48)

If Conte wants Lukaku to press from the front like Costa has done, he'll have to change his game. Sixty-five forwards made an interception last season. Lukaku wasn't one of them. Sixteen players made more than his nine tackles. Costa, in contrast, ranked in the top seven in both of those metrics.

Harrying opposition defenders? Working the channels? Holding the ball up and bringing others into play? They're not strengths associated with Lukaku, who completed just 66 per cent of his attempted passes last season.

Defending from the front? Romelu Lukaku has managed just one interception and 33 tackles over the past three years. Diego Costa has 18 and 52, respectively.

Of course, Lukaku's primary role isn't about defending. He's a goal-getter. But those numbers underline the fact he will have to adapt at Chelsea if he is going to replace Costa. He must find a way to affect the game even when he's not scoring.

"One of my big criticisms of him is when he doesn't score sometimes you don't see him," said Sky Sports pundit Jamie Carragher, who believes Lukaku should study the performances of former Chelsea hero Drogba.

"With Lukaku you can't help but draw comparisons with Drogba because of his size, power and pace. But Drogba could still be man of the match without scoring. He could dominate a back four or two centre-backs.

Great players don't just perform themselves, they affect other people. Jamie Carragher

"When Lukaku doesn't score I still feel he should be having a major impact on the game and that's something going forward that he's got to do. Great players don't just perform themselves, they affect other people.

"I think he's definitely got the potential to be world class with his goal-scoring record. I just think if he could improve and become an all-round player he'd be well on his way to getting there."

Lukaku would relish those Drogba comparisons, having previously said his aim was to "be a legend" at Stamford Bridge. But he has work to do to prove to his doubters he can seize his second opportunity to make his mark at Chelsea.

The pressure will be on - but Lukaku will be confident of rising to the challenge.