Romelu Lukaku returned to Chelsea as the missing piece of the jigsaw.
Now, the £97.5million striker is in serious danger of joining a long list of big-money strikers who have become expensive mistakes at Stamford Bridge.
Chelsea striker Lukaku is struggling for form and confidence and needs an upturn in fortunes to stop following the likes of Fernando Torres, Alvaro Morata and Andriy Shevchenko.
Torres was a £50million flop, Morata never lived up to expectations after his £60m move and Shevchenko was Roman Abramovich’s dream £30m signing who never lived up to his reputation while at Chelsea.
Chelsea boss Thomas Tuchel was honest enough to admit it is “on me” to make sure that Lukaku does not follow the same path, but firmly believes the No9 will come good.
Maybe the previous strikers have struggled when judged against Didier Drogba - their best and most successful striker in recent history - but also Chelsea are arguably not playing to Lukaku’s strengths.
Tuchel said: “There’s even a history of strikers struggling at Chelsea so it is not the easiest place in the world for strikers. I don’t know why it is like this but maybe it is.
“Chelsea is a team considered as a strong defensive, physical team. We demand a lot from our strikers in terms of defending. We want to be a physical, hard working group that is not shy to make it a physical game and not only a skilful game, that maybe plays a part.
“We have many games throughout our year together where we created many chances, many deliveries and struggled a bit in the conversion. Now in the moment we struggled to create too many big chances for our strikers, this is a normal period in a long season.
“We are on the subject, well aware and like always it is not just one reason for the problem. It is a very complex sport, we try to keep playing with faith in what we do and in belief. It’s a team effort. From there we go.
“But still, we can also play and win games without any player. This is our job, what we want to do, what we try when we have injuries and Corona cases. It’s on us, on me to adapt and find solutions. Romelu will always be part of the solution.”
The plain truth is that Lukaku arrived with the hope that he would provide the goals to transform Chelsea from being a cup side - having won the Champions League last season - into a more consistent title-winning team.
But Lukaku has managed just five goals in the Premier League and two in Europe; Chelsea look a more complete, fluid team when they use Kai Havertz as a false nine because they have not given the Belgium star enough service.
Lukaku played the 90 minutes against Crystal Palace on Saturday and, while only touching the ball seven times, it is definitely down to Tuchel to try and make the record signing work.
In fairness, Lukaku did score in both games in the Club World Cup - and now the business end of the season in the Champions League has arrived with Chelsea red-hot favourites to progress into the quarter-finals.
Tuchel admits he was in favour of scrapping the away-goals rule in Europe and says it will not change his approach in either game.
Tuchel added: “For us it changes nothing in the approach for the game on Tuesday. We will try to keep a clean sheet, try to attack as good as possible.
"If at all it changes a little bit in at all the approach to the second leg, we don’t have to think as much ‘Do we have to score a goal? What do we have to do?’
"It’s easier to adapt, let’s get the two games and get them played, do the mathematics and if it's level we go to extra-time.”