Real Madrid vs Chelsea: How Kai Havertz has replaced Romelu Lukaku to lead the line for the Blues

The news that their side would be forced to go into the biggest game of their season without their record signing would usually be enough to induce at least a mild form of panic among a fanbase, but the fact that Romelu Lukaku's injury-enforced absence from Tuesday's trip to Real Madrid has failed to generate more than minor headlines reflects just how much he has struggled since returning to Chelsea this season.

Lukaku was signed from Inter Milan for £97.5m last August and was seen as the final piece of the jigsaw that would allow Thomas Tuchel to solve the puzzle of how to end Manchester City and Liverpool's domestic dominance.

But despite striking four times in his first four games - which included a goal in an impressive second Chelsea debut at Arsenal and two against Aston Villa - the goals quickly dried up for the Belgian.

Lukaku has continued to underwhelm to such an extent that he now finds himself behind Kai Havertz in the pecking order to be the No 9 at Stamford Bridge, and the German is set to lead the line again when Chelsea bid to overturn a 3-1 deficit in the Bernabeu and progress to the Champions League semi-finals.

Lukaku has been ruled out of the game with an Achilles injury, but his absence is unlikely to have disrupted Tuchel's gameplan, given the 28-year-old's only starts since mid-February have come in the FA Cup.

Lukaku did make an appearance from the bench in the first leg against Real but, with his side two goals down and in desperate need of inspiration, he missed a glorious chance just minutes after coming on, a scene that perfectly summed up how his return to the club he supported as a child has gone sideways.

Lukaku will now be deprived of the chance to make amends for that miss in the second leg and will instead be forced to watch from the sidelines, where he may contemplate where things have gone wrong for him this season, why Havertz has been able to succeed where he has failed, and whether his return to west London was in fact doomed from the start.

More goals, more passes, more ball recoveries - the case for Havertz over Lukaku

Since Lukaku's now infamous performance at Crystal Palace on February 19, which saw the man signed for nearly £100m touch the ball just seven times in 90 minutes, he has started just two matches, both of which were against lower league opposition in the FA Cup.

While that afternoon at Selhurst Park appeared to be a tipping point for Lukaku, it was also a turning point for Havertz, who replaced the Belgian as Thomas Tuchel's preferred No 9 after that game and has gone on to score seven goals in nine starts.

The fact that Havertz is grasping his opportunity to lead the line is welcome news for Chelsea given the sizeable investment they made in him nearly two years ago, but it has presented the problem of what to do with Lukaku.

It seems untenable for a player of Lukaku's undoubted quality to be warming the bench for a prolonged period, but the statistics below show why Tuchel's preference for Havertz to lead the line is entirely justified.

The German scores more goals per 90 minutes in the Premier League than Lukaku, while he also attempts more shots and steers more of them on target.

Havertz's comfort playing in various positions - he has spent much of his career playing either on the wing or behind a main striker - may explain why he offers far more in the build-up than Lukaku, as shown by the fact that he completes more than double the amount of passes than his team-mate per 90 minutes.

It's not just Havertz's personal statistics that justify his inclusion at the expense of Lukaku; as the graphic below shows, Chelsea perform better in a variety of metrics - including goals, final-third completed passes and ball recoveries in the final third - when Tuchel plays his countryman as his central striker.

Why has Lukaku failed to find his feet?

Needless to say, Lukaku's total of five goals and one assist in 20 Premier League games since returning to Chelsea is far less than he or the club expected, and not what the European and world champions paid all that money for.

The 28-year-old's output is even more surprising when contrasted with his exceptional performances for Inter Milan in Serie A last season, when he played a key role in their first Italian title for 11 years.

Only Cristiano Ronaldo - then of Juventus - scored more goals than Lukaku in Serie A in the 2020/21 campaign, but since returning to the Premier League, Belgium's all-time top scorer is recording fewer goals, shots, touches in the box and assists.

It's hard to make the argument that Chelsea don't provide enough service to their striker. Compared to the Inter side in which Lukaku thrived last season, Tuchel's team attempt more final-third passes, more long passes, more through balls and more crosses.

One key difference between the two sides, though, is that Lukaku was supported by Lautaro Martinez last season in Antonio Conte's preferred 3-5-2 formation, whereas he usually has two attacking midfielders playing behind him when leading the line for Chelsea. Inter's system allowed Lukaku to occupy positions in the middle and in the right channel, whereas he plays a more central role under Tuchel.

In Lukaku's controversial interview with Sky Italy at the end of last year, he questioned the head coach's system, saying Tuchel had "decided to play a different formation". Was that a reference to the striker's desire to play with a strike partner?

But it's not as though Tuchel hasn't given Lukaku the opportunity to play alongside another striker this season - he has done so on six occasions, with the Belgian's output declining in a number of key metrics compared to when he lines up as a lone striker.

Chelsea lined up in a 3-5-2 formation for the visit of Manchester City in September, with Lukaku up front alongside Timo Werner, but the Blues failed to record a shot on target in a 1-0 home defeat that caused Tuchel to admit he had got his tactics wrong.

Does Chelsea's style stifle their forwards?

But while the statistics make grim reading for Lukaku, it's perhaps harsh to single him out as an underperforming forward in Chelsea's team. In fact, there's an argument to say many of the Blues' attacking players aren't pulling their weight in front of goal.

Mason Mount is the only member of Tuchel's squad to reach double figures in the Premier League this season, while none of Lukaku, Timo Werner, Christian Pulisic, Hakim Ziyech or Callum Hudson-Odoi have scored more than five times in the top flight.

Chelsea's forwards have even been shown up by their more junior team-mates currently on loan around the Premier League. Conor Gallagher has scored more league goals this season than any Blues player other than Mount, while Armando Broja's six strikes is just one behind Havertz.

But on the other hand, Chelsea have a remarkable knack of finding goals from other areas, particularly their defenders. Reece James is the top-scoring defender in the Premier League with five goals, while Chelsea's defenders as a group have combined to score 19 times this season - just one fewer than Norwich's entire team have managed in 31 matches.

There is also an argument to suggest that Chelsea are a relatively conservative side, given they are world and European champions and lie third in the Premier League. They often line up with two central-midfielders screening three centre-backs in Tuchel's trusted 3-4-3 formation, and compared to Liverpool and Manchester City, Chelsea attempt fewer final-third passes, fewer shots and fewer crosses, while they also create fewer big chances and score fewer goals.

On the other hand, only Liverpool and City have conceded fewer league goals or completed more passes than the Blues. This suggests that Tuchel's style is based on defensive solidity and control of the ball, and that a reduced output from Chelsea's forwards is perhaps a consequence of such an approach.

Lukaku following in famous footsteps?

Tuchel suggested in the wake of Lukaku's seven touches at Palace that history may be against his striker in his quest to become a regular goalscorer at Stamford Bridge, saying: "There is a history of strikers struggling a little bit at Chelsea so it may not be the easiest place in the world for strikers."

"I don't know why it's like this," Tuchel added. "In my opinion, Chelsea are a team considered a strong defensive team, a physical team, that has a certain attitude when in competitive football."

Lukaku is certainly in good company when it comes to being a big-name striker who has failed to meet expectations at Stamford Bridge. Andriy Shevchenko, Fernando Torres and Alvaro Morata all arrived for huge fees but struggled to varying degrees, while Radamel Falco and Gonzalo Higuain endured underwhelming loan spells in west London.

In fact, since Didier Drogba - undoubtedly Chelsea's best striker over the past two decades - left the club for the final time in the summer of 2015, only Diego Costa, who scored 52 Premier League goals in 89 games, could claim to have been an unqualified success up front for the Blues.

Tammy Abraham's total of 21 goals in 56 league games is perhaps better than would be expected given Tuchel barely used the England striker before he was sold to Roma last summer, while Olivier Giroud's 17 in 75 doesn't reflect the value that he offered as a target man.

However, there is no doubt that Chelsea have lacked a prolific scorer for a number of seasons, which is demonstrated by the barely believable fact that Eden Hazard's 28 goals makes him their highest scorer in the Premier League since the start of the 2017/18 campaign, even though he left the club nearly three years ago.

For context, that places Lukaku's Belgium team-mate joint-33rd for goals in the top flight in that time. Over the same period, Harry Kane has scored 100 times, while Mohamed Salah leads the league with 115.

Lukaku may look at this and believe Tuchel was right when he said history may be against him - after all, it seems that scoring goals on a consistent basis as Chelsea's No 9 is far harder than it should be. But it's also clear that Lukaku isn't carrying out the job he was brought in to do, which was to score the goals that allowed the Blues to close the gap on Liverpool and City.

In the meantime, Tuchel has settled on a system without Lukaku that has continued to allow his side to pick up points, while Havertz has filled the void left by the Belgian to such an extent that it's tough to see how the record signing reclaims his place in the side as the season enters its final stretch.