With Romelu Lukaku set to return to Inter Milan, why can't Chelsea find a reliable striker?

Perhaps Thomas Tuchel saw the writing on the wall when, in February, he admitted: "There is a history of strikers struggling a little bit at Chelsea. It may not be the easiest place in the world for strikers."

Tuchel's comments came in the wake of Romelu Lukaku's infamous performance at Crystal Palace which saw him touch the ball just seven times. It was another two months until the striker was handed another Premier League start.

"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."

Four months after the head coach's confession, Lukaku - the striker signed for a club-record £97.5m from Inter Milan just 11 months ago - is set to return to Serie A after adding his name to the list of goalscorers that have struggled to make their mark at Stamford Bridge.

The 29-year-old arrived as one of the most feared strikers in world football after scoring 64 goals in 95 games during two seasons with Inter, the second of which saw the club claim their first Serie A title in 11 seasons.

But he looks like leaving west London after finding the net just 15 times during the 2021/22 campaign, while he courted controversy with his unsanctioned interview with Sky in Italy in December in which he questioned Tuchel's tactics and expressed a desire to return to Milan.

Hopes were high that Lukaku, who first joined Chelsea as a teenager in 2011 but left in 2014 after failing to break into the first team, would be the answer to the Blues' troubles in front of goal. But it has proved to be an unhappy reunion for both parties.

Lukaku not the first to fail live up to hype

Perhaps Lukaku can take some solace in the calibre of strikers that also failed to meet expectations after making high-profile moves to Chelsea. Andriy Shevchenko, Fernando Torres and Alvaro Morata all arrived for huge fees but struggled to varying degrees, while Radamel Falcao 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 left for Roma, while Olivier Giroud's 17 in 75 does not reflect the value that he offered as a target man.

However, there is no doubt 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 three years ago.

For context, that places Lukaku's Belgium team-mate 34th for goals in the top flight in that time. Over the same period, Harry Kane has scored 105 times, while Mohamed Salah leads the league with 118.

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

While Lukaku's performance against Crystal Palace may be seen as the nadir of his second spell at Chelsea, he did have a bright (albeit brief) spell back in the side in May, when he scored three goals in two games against Wolves and Leeds.

However, those promising displays were followed by uninspiring outings in the FA Cup final against Liverpool and Leicester in the Premier League, and he spent the entirety of the last game of the season - a 2-1 home win over Watford - warming the bench.

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

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

It quickly became clear that having a player of Lukaku's undoubted quality warming the bench for a prolonged period was untenable, but the statistics below showed why Tuchel's preference for Havertz to lead the line was entirely justified.

The Germany international scored more goals per 90 minutes in the Premier League than Lukaku, while he also attempted more shots and steered 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 offered far more in the build-up than Lukaku, as shown by the fact he completed more than double the amount of passes than his team-mate per 90 minutes.

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

Why did Lukaku fail to find his feet?

Needless to say, Lukaku's output since returning to Chelsea is not what the world champions paid all that money for, and it is even more surprising when contrasted with his exceptional performances for Inter two seasons ago.

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 has recorded fewer goals, shots, touches in the box and assists.

It's hard to make the argument that Chelsea did not provide enough service to their striker. Compared to the Inter side in which Lukaku thrived, Tuchel's team attempted 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 at the San Siro in Antonio Conte's preferred 3-5-2 formation, whereas he usually had 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 played a more central role under Tuchel.

But it's not as though Tuchel did not give Lukaku the opportunity to play alongside another striker this season - he did so on several occasions, including for the visit of Manchester City in September, when the Belgian played up front alongside Timo Werner.

However, Chelsea failed to record a shot on target in a 1-0 home defeat, after which Tuchel said: "We were too deep. There was no connection [with Lukaku] and this was a team problem, not an individual problem."

Chelsea's defenders showed up forwards in front of goal

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 are not pulling their weight in front of goal, which goes a long way to explaining why Tuchel is keen to sign Raheem Sterling - who has more goals and assists in the Premier League than any Chelsea player in the last five seasons - this summer.

Mason Mount was the only member of Tuchel's squad to reach double figures in the Premier League last season, while none of Timo Werner, Christian Pulisic, Hakim Ziyech or Callum Hudson-Odoi scored more than six times in the top flight. Chelsea's forwards were even shown up Conor Gallagher, whose eight goals from midfield for Crystal Palace matched the totals achieved by Lukaku and Havertz.

But on the other hand, Chelsea had a remarkable knack of finding goals from other areas - particularly defence. Reece James was the joint-highest-scoring defender in the Premier League with five goals, while Chelsea's defenders as a group combined to score 22 times - just one fewer than Norwich's entire team managed in 38 matches.

Another factor perhaps hampering Chelsea's forwards has been the fact that the club have had four head coaches in the last five seasons, each of which have brought their own tactics, preferences and demands. This undoubtedly makes it harder for players to be confident of having a regular spot in the team, while it also creates fewer opportunities for players to get comfortable with each other in a particular system.

Of the top five scorers over the past five Premier League seasons, three - Mohamed Salah, Raheem Sterling and Sadio Mane - have played under just one manager the entire time, while the other two - Harry Kane and Jamie Vardy - have been almost guaranteed to start as No 9s regardless of who has been in the dugout.

But with the arrival of Todd Boehly as owner, as well as the pursuit of Sterling and the willingness to move on from Lukaku, it appears as though Chelsea are backing Tuchel to remain in charge for the long term. In doing so, the Blues will hope he can build a team capable of supporting a striker that can end their goalscoring issues.