The summer transfer window of 2020 is not likely to be a period that any Chelsea fan will ever forget.
After securing a top-four finish in their first season under the stewardship of club legend Frank Lampard, Chelsea had aspirations to take the next step and cement themselves as genuine title contenders.
In a bid to challenge the likes of Liverpool and Manchester City at the very top of the table, Roman Abramovich - the Blues owner - supplied Lampard with a transfer war chest to assist his ambitions of becoming the first English manager to win the Premier League.
Spending more than £220million, Chelsea, who face Championship side Luton Town in the FA Cup fourth round on Sunday afternoon, drafted in seven new signings, including the likes of Thiago Silva, Ben Chilwell and Timo Werner.
By the time Chelsea kicked-off their 2020/21 Premier League campaign on Monday, September 14, there was genuine optimism amongst the club's supporters that they had a squad capable of challenging Jurgen Klopp's Liverpool and City in the quest for English football's ultimate prize.
Up until early-December, Chelsea looked as though they were genuine contenders, topping the table after a 3-1 home triumph over Leeds United. Since then, however, the Blues have won just two of their last eight league matches, losing five.
Whilst it is only natural that teams, whoever they are, will experience rough patches during a 38-game season, Chelsea should be doing far better than they currently are with the money that they have spent.
Out of the £220million-plus they spent during the summer, the west London club's biggest investment was the addition of Kai Havertz from Bayer Leverkusen. The Germany international arrived at Stamford Bridge for an initial fee of £72million, with the deal potentially rising to £90million with add-ons.
Having already landed Hakim Ziyech and Werner, Havertz was seen as the final piece in the jigsaw to form Lampard's new-look attacking line.
His arrival in England was met with excitement and intrigue, as he had been lavished with praise by so many big names from within the football world in recent years, including the likes of Klopp, Germany international Thomas Muller and even Lionel Messi.
As well as those three revealing their admiration for Havertz, former Chelsea manager Maurizio Sarri did as well. Ahead of a Champions League clash between Juventus and Leverkusen back in November 2019, the Italian, who is currently out-of-work, made a special point during his pre-match press conference to outline the threat Havertz would pose to his Juve players.
Sarri, as quoted by Serie A analysis, said: "He is a player who combines excellent physical qualities with great technical skills. At the moment they are using him mainly as an attacking-midfielder behind the central forward or as a winger.
"I think he is a complete player that could also play as a midfielder.
"He is a player born in 1999... with those qualities and that personality it makes you think it is certain he will become one of the most important players in Europe."
Admittedly, Havertz still has age on his side, as he does not turn 22-years-old until June, meaning he has no shortage of time to blossom into the player so many believe he will do.
However, after Chelsea made the decision to spend more than an initial fee of £70million on securing his signature, he has so far failed to live up to expectation, scoring just six goals in 23 appearances in all competitions.
In fairness to the youngster, he has had to battle against Covid-19, but even before contracting the virus he was struggling to adjust to his new surroundings.
Now, as we approach the latter stages of January, Havertz still appears to be in that adjustment stage, with his performance against Leicester City on Tuesday evening, which saw Lampard's troops beaten 2-0, leaving a lot to be desired. He was ineffective in the first half, as Leicester's midfield gave him no chance at all to impose himself on the game.
As outlined above, the midfielder is still young, needs time to settle and acclimatise himself to the Premier League, but he has a long way to go before he can prove to Chelsea's supporters that he is capable of doing what Sarri believes he can.
