Where has it gone wrong for Romelu Lukaku and Chelsea?

Romelu Lukaku was hailed as the "missing piece" in the Chelsea line-up when he signed for the club in the summer. But the striker appeared to simply go missing last weekend when he made just seven touches in 90 minutes against Crystal Palace, a Premier League record low.

And Blues manager Thomas Tuchel said it was not the moment "to put him into the next fire" when he elected to start Kai Havertz instead of Lukaku up front against Lille on Tuesday.

Havertz, who scored the winner in last season's Champions League final, again proved he was the man for the big occasion by opening the scoring and Tuchel is faced with a dilemma over who should lead the line in Sunday's EFL Cup final against Liverpool.

Lukaku, signed by Chelsea after his scintillating role in Inter's title-winning campaign of 2020-21, was supposed to be the final piece of the jigsaw for a Blues side who had been wasteful in front of goal, scoring 58 goals from an xG of 64 last season.

However, after three goals in his first three league appearances, the Belgian has scored only twice more in the top flight since mid-September.

His 24-goal domestic tally last term was boosted by being on penalty duties – Jorginho is Chelsea's first-choice penalty-taker – but even excluding spot-kicks he still averaged 0.56 goals a game with Inter compared to 0.38 this season.

That is Lukaku's poorest return since 2014-15 and he averaged around 0.5 goals per game under Jose Mourinho and Ole Gunnar Solskjaer at Manchester United before his move to Italy, proving that it is not just a case of Serie A being weaker than the Premier League.

The table below compares Chelsea's numbers this season in games where Lukaku played at least 45 minutes:

Chelsea with and without Lukaku in the Premier League

The goals-per-game average is skewed by the Blues putting seven past Norwich without him but the number of games in which they have scored two or more goals is a better guide to the consistency of their attacking threat.

Chelsea's numbers are better without him in the side, although it is important to note that the sample of games he played in includes both fixtures against champions Manchester City and the draw at Liverpool where they played the entire second half with ten men.

Factoring that in, it would be harsh to say that Chelsea are significantly worse with Lukaku in the side but they certainly are not noticeably better, which is not what a club wants from a player who cost £97.5m.

The graph above shows the attacking involvement and threat of forwards in the Premier League this term. While players have varying roles, Lukaku is far removed from the forwards from the division's top two clubs Manchester City and Liverpool, who are clustered towards the top-right of the graph. He has also posed less of a threat than strikers such as Tottenham's Harry Kane and United's Cristiano Ronaldo towards the upper-centre of the graphic.

Tuchel suggests a lack of confidence is partly to blame but there must also be doubts over whether his system plays to Lukaku’s strengths.

At Inter he generally played alongside another forward such as Lautaro Martinez. That allowed him more freedom to find space and either run at or in behind defenders, rather than being the lone focal point, often with his back to goal, as he is asked to do at Chelsea.

The bar charts above show how Lukaku is not being picked out by his Chelsea teammates as he is receiving just 20 passes per game, down almost a third from the 29.2 he was averaging at Inter last season.

That means he is getting to turn and carry the ball much less frequently and is also having significantly fewer touches in the attacking third. The end result is fewer shots per game and those shots are coming, on average, from less dangerous positions.

How much Lukaku should adapt to his manager's wishes or vice versa is open to debate. One significant factor is that Chelsea have lost some of their cutting edge since Reece James joined fellow wing-back Ben Chilwell on the sidelines just after Christmas.

James is reportedly close to returning, which would restore some dynamism out wide as he had scored four goals and provided five assists before his injury.

Lukaku scored in both games of Chelsea's Club World Cup triumph earlier this month but Liverpool pose a far stiffer challenge than Al Hilal and Palmeiras so Tuchel may opt to stick with Havertz for Sunday's final.

The table below shows Lukaku's and Havertz's individual stats in Premier League and Champions League games in which Fbref has them playing as a central forward this season:

Lukaku v Havertz (when playing as a central forward)

Lukaku has been slightly more clinical but Havertz is more involved, knitting things together, and offers more defensively, so Tuchel may decide that the German is the best fit for Chelsea, at least for the time being.

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