Still only 21, the striker followed up a successful loan spell at West Brom in 2012-13 with a stint at Everton in which he scored 15 Premier League goals.
With that Group D clash days away, Lukaku also bagged a hat trick in a 5-1 friendly win against Luxembourg on May 26, completing his scoring exploits for the night with a sublime goal, using a step-over to beat one defender, before chopping past another and finishing at the near post.
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The Belgian is primed to make a big impact at his first senior international tournament in Brazil, alongside Eden Hazard and a host of other Premier League-based stars.
At club level, however, Lukaku’s future remains uncertain heading into the summer.
Chelsea battled with Tottenham and Arsenal to sign a teenage Lukaku for around 21 million euros in 2011, but the striker has rarely been involved at Stamford Bridge following a series of managerial changes.
The second coming of Jose Mourinho has done little for the former Anderlecht prodigy by way of first-team opportunities. Lukaku made three appearances off the bench at the start of the season, but after missing a penalty in the UEFA Super Cup defeat to Bayern Munich at the end of August, he was promptly dispatched to Goodison Park.
Mourinho signed the more experienced Samuel Eto’o, with whom he enjoyed a fruitful relationship at Inter, but the Portuguese repeatedly voiced his frustrations over the lack of production from his front line last season. Between them, the trio managed a combined total of 19 league goals – just four more than Lukaku on his own - as the Blues fell short in the race for the title.
Eto’o, who scored nine times in the Premier League, has not been offered a contract extension, while Mourinho has described Fernando Torres as “not the kind of guy who’s going to score goal after goal”.
The Portuguese has suggested Chelsea could keep both Torres, who is a target for former club Atletico Madrid, and Demba Ba, though the Senegal international is anything but indispensable, while Diego Costa looks set for Stamford Bridge.
The Atletico Madrid striker is understood to have already agreed to a €43 million move to Chelsea, after playing a huge part in Diego Simeone’s side’s league title triumph and run to the Champions League final with a combined 35 goals over both competitions.
So where does that leave Lukaku? It might seem baffling to some that a strong and powerful, but also mobile striker who scored all of his goals inside the penalty area with a mixture of both feet and his head might not have a place in the Chelsea squad next season.
But as Juan Mata would attest, if you do not fit in Mourinho’s system, you can find yourself surplus to requirements at Stamford Bridge, regardless of potential ability.
While Chelsea enters the transfer market for a front man once again, Lukaku just wants to play.
"As a youngster, you normally have to play,” he said towards the end of last season. “How will you be one of the best not playing? Look at (Wayne) Rooney, (Cristiano) Ronaldo, (Didier) Drogba - every top striker. They always played.
"They played constantly, always, all the time. Games, games, games. I just want to be one of them - that is my ambition, I just want to be one of those guys.”
As such, plenty of Premier League clubs will likely monitor Lukaku’s situation with interest over the summer. Former Tottenham boss Tim Sherwood indicated Spurs would weigh up a move prior to his departure, though much will depend on new head coach Mauricio Pochettino and the plans he draws up with director of football Franco Baldini.
Everton, meanwhile, will doubtless keep tabs on its former loan star. Roberto Martinez has suggested as much.
"We'll see what the best thing [is] for everyone,” Martinez said. “But everything will be in stages: how Chelsea are doing in their own squad and how that frees some players.
"It's going to take a bit of time and I don't think Romelu's situation is going to be resolved before the World Cup, in truth. I think it will be after the World Cup."
Borussia Dortmund, too, has emerged as a contender for the striker and, unfortunately for Everton, a big performance in Brazil could attract more interest in Lukaku and price the Toffees out of the running.
If Chelsea is willing to listen to offers for Lukaku this summer, there is sure to be a scramble for his signature.