As such, Chelsea was thought to be fortunate to sign him.
Seemingly strong, physical and lethal in front of the goal, Lukaku looked like the club's long-term answer to the departure of Didier Drogba.
Flash-forward to 2014, and Lukaku may be on his way out after what seems like only a handful of appearances for Chelsea.
Despite Chelsea's urgent need for a new striker, the Belgian—who has spent the last two years on loan to West Bromwich Albion and Everton—has failed to convince manager Jose Mourinho of his value.
Should Chelsea decide to sell him, where exactly he would go is not yet clear. It became apparent, though, that the Belgian striker regards the World Cup as the perfect opportunity to show the world—including Mourinho—exactly what he's worth, harshly voicing his discontent about the situation to Sky Sports.
It isn't just words coming from Lukaku. The striker has been putting in performances on the pitch as well.
During Belgium's first friendly against Luxembourg, for example, Lukaku scored a hat-trick, and in their second friendly against Sweden, he bagged another goal. Even with Eden Hazard and Kevin De Bruyne surrounding him, the striker constantly looked like one of the most lethal players on the pitch.
Against Tunisia on Saturday, Lukaku made only a brief appearance during the second half, where it shortly looked like disaster had struck on a blocked shot that forced him to limp off the pitch as silently as he had come on.
It quickly transpired that the injury was probably a minor enough one not to affect his playing in the tournament, per the Daily Star, but the apprehension that followed that evening demonstrated Lukaku’s worth to the "Rode Duivels."
After the catastrophic injury that ruled Aston Villa's Christian Benteke out of the World Cup, the Belgians did not want to lose another in-form striker.
In Brazil, Belgium will need Lukaku not only to be injury-free, but also as motivated by his precarious situation at Chelsea as he has shown himself to be during Belgium's friendlies. As the man looked at to help turn the creativity of players like Hazard and De Bruyne into goals, they need him to step up.
In this way, while Lukaku needs Belgium, Belgium also need Lukaku, and the conditions are perfect for the striker to shine. As the Rode Duivels will be looking to prove doubters of their dark-horse credentials wrong, Lukaku will be doing everything he can to impress clubs who might be willing to sign him after the tournament.
Proving to Mourinho that the striker Chelsea has needed for a while was already theirs will, of course, provide an added pleasure for all those involved.