Chelsea must have known Romelu Lukaku's ceiling; it seemed everyone knew his potential when he signed for the west Londoners from Anderlecht in 2011. Thought to be Didier Drogba's heir apparent, the then-18-year-old cost £18 million, which was considered near robbery.
Many Blues supporters thought they had captured their next great centre-forward, but after two seasons, it was obvious Lukaku's journey was not going as planned. Attempting to usurp Drogba and Fernando Torres in Chelsea's striker depth chart was a bridge too far for the teenager, so he was sent on loan.
Playing 2012/13 with West Bromwich Albion, the Belgium international played 35 Premier League games and scored 17 goals—the sixth-best tally in England's top flight. His season-long performance (including a final day hat-trick against Manchester United) was worthy of a proper chance in Chelsea's first team.
Jose Mourinho became the Blues' manager before the 2013/14 season and was willing to give Lukaku scraps. Torres and Demba Ba were the senior members, but their younger team-mate played three times in Chelsea's opening four matches.
His final game for the club was 2013's UEFA Super Cup.
Mourinho and Bayern Munich head coach Pep Guardiola—in a competition neither of them earned—oversaw a dramatic 2-2 draw. Javi Martinez leveled scoring in the 120th minute of extra time, and penalties were required. All nine spot-kicks before Lukaku's were made, but the Belgian missed his, giving Mourinho's archrival his first trophy at the Bundesliga club.
Two days prior, Chelsea bought Samuel Eto'o from Anzhi Makhachkala, and that signing—combined with Lukaku missing his penalty—sparked the Belgian's next loan move to Everton.
At Goodison Park, the young striker found a home. Surrounded by other burgeoning talent like John Stones and Ross Barkley, manager Roberto Martinez had a certificated place readied. In his first season in Merseyside, Lukaku played 31 Premier League games and scored 15 times.
Demanding first-team football at Stamford Bridge, Lukaku was never going to get a proper chance in west London (especially not when Mourinho signed Diego Costa and re-signed Drogba), hence, before the 2014/15 season, Chelsea sold possibly their best attacking prospect to Everton for £28 million.
Sixty-one goals in 118 Everton appearances (from all competitions), suggests the now-22-year-old made a fantastic career decision by permanently leaving Roman Abramovich's club.
Directly responsible for 31 goals this season, the Belgian's name is hot on the transfer rumour mill.
Paris Saint-Germain, Real Madrid and Juventus have been linked with Everton's in-form striker, per Gazzetta Dello Sport (h/t the Daily Mail), after he told Sky Sports News HQ while on international duty: "I'm 23 next summer and it would be nice to play in the [UEFA] Champions League next season."
The questions circling now have little to do with ability, and more to do with expectation. At Everton, Lukaku does not have massive pressure on him and is enjoying the perfect environment to grow. Once taken out of that nurturing environment, though, and tasked with carrying a heavier load, can he deliver?
Chelsea were under little obligation to play him, £18 million was a decent price tag, but the centre-forward's next move could be upwards of £50 million, if ESPN FC's Chris Borg is accurate.
Opportunities will be given, but not with the same slack afforded at Everton. Should the likes of PSG or Real Madrid swoop in for Lukaku, they will demand a player ready to score goals at the highest level. Never playing in the Champions League group stages, can a club justify spending £50 million on a player only proven in the UEFA Europa League?
"Probably" is the answer.
Lukaku would require another season of learning. Acclimating to the intensity and pressures the so-called "superclubs" entail will be a challenge, but at every stage in his career (except for 2013's UEFA Super Cup), the 22-year-old has met whatever expectations.
Taking the comparison many like to use (even if massively oversimplified), Drogba made his senior debut for Ligue 2's Le Mans as an 18-year-old. His breakout season was at Olympique de Marseille in 2003/04, as a 25-year-old. Lukaku was already signed by one of Europe's top clubs at 18; moreover, he has three years left before reaching 25.
In that respect, Chelsea made a massive blunder selling Lukaku, but he needed to leave for his own development (see Nemanja Matic). The Sun's Phil Cadden suggests England's defending champions want him back, but this time, they face heavy competition with clubs in far better positions, with far more clout.
For Lukaku's own development, another great season with Everton wouldn't hurt. That said, if big money comes calling, and the prospect of hearing the Champions League anthem at the Parc des Princes, Juventus Stadium or Santiago Bernabeu is available, he would be foolish to ignore it.