Arsenal have made plenty of financial missteps in their pursuit of a return to the top, with the later years of Arsene Wenger's diminishing reign giving way to Unai Emery's short and unsuccessful tenure.
Even Mikel Arteta is not completely free from blame when it comes to failed transfers, but fortunately, he is the one who has come the closest to bringing elite honours back to the Emirates.
The Gunners are a prestigious club – one of the biggest and best in England – so their many years floundering outside of the Champions League spots drew widespread ridicule from many of their rivals.
It was easy to enjoy their downfall when, at their peak under the legendary aforementioned Frenchman, they went toe-to-toe with the great Manchester United teams of the past under the equally outstanding tenure of Sir Alex Ferguson.
Fans of the north London club expect the best because that is all they have ever known, and so the demands placed upon each new boss and every expensive signing seem to be intensified. Some thrive under this added pressure, but as we have seen across the last decade, plenty more tend to wilt.
As such, there is a depressingly lengthy list of duds, making up quite the rogues' gallery for the Gunners and KSE.
Who is Arsenal's worst-ever signing?
Whilst it might be difficult to pinpoint exactly who is the worst signing in their history, given there have been so many, Nicolas Pepe's recent departure arguably marks one of the more embarrassing deals that instantly spring to mind.
After all, the Ivory Coast international has seen his contract mutually terminated to allow him to join Turkish side Trabzonspor, just four years after KSE paid a club-record £72m fee for his services.
However, despite that debacle, there were plenty of other smaller failures who, whilst not quite as renowned due to the far smaller price tag, each did their own financial damage to the club.
One such example is Lucas Perez, who was one of their 2016 signings made just four years before Wenger would announce his retirement. Upon capturing his man, the boss noted: "He's not only a goalscorer, he's a guy who combines well with partners, who can give a final ball and makes good runs. He's got a good eye for goal and had an outstanding season last year."
It's fair to say that his words were proven horrifically wrong, with many questioning the decision to clearly opt for a cheaper alternative when they craved a top striker.
Arsenal legend Ian Wright even claimed after just one game: "Arsenal need a striker. I thought we would see someone more direct. Hopefully that will happen. It seemed to me that he’s a winger."
Either way, he remained profligate, and with chances limited, he failed to come even close to paying back the fee expended to secure his services.
How many goals did Lucas Perez score for Arsenal?
The Spaniard would make just 21 appearances, scoring seven goals and recording a mere three assists, which included a Champions League hat-trick.
Despite that, he would blame the club for his shortcomings in a revealing interview: "I feel cheated. In February I was not allowed to leave for China with the promise that I would play more and after that I had even fewer opportunities.
“Last year he (Wenger) told me that he understood that I was upset. I think this season things will get worse, so help me out.
“Since I have been a professional footballer, I've felt happiest in Deportivo, surrounded by my family and my friends. Put yourself in my place.
“They (Arsenal) are not behaving well with me. To take the shirt number without telling me and to give it to a companion — it seems to me that it is the last straw. I can't continue this way. I have given everything, but that has not been reciprocated, so I can't stand it any longer. I want to leave and be happy.”
With his feelings known, he would move on to West Ham United where his struggles would continue. After bouncing around his homeland, the 34-year-old has finally returned to his beloved Deportivo La Coruna, where he still plays today.
How much did Arsenal pay for Lucas Perez?
Although his time at the club marked an ugly affair, in which nobody really seemed to benefit, it was the Gunners who certainly came out worse given the financial damage his move took.
Whilst it might not seem that damning to lose the £17.1m spent to sign him, given his goal contributions it actually turned into quite a lucrative failure that cost plenty for every goal involvement he gave.
18/19 Premier League (West Ham United)
3
0
17/18 La Liga (Deportivo La Coruna)
8
6
16/17 Premier League (Arsenal)
1
0
15/16 La Liga (Deportivo La Coruna)
17
10
14/15 La Liga (Deportivo La Coruna)
6
3
All stats via Transfermarkt
It is also worth noting that the forward came in during a summer when they also bought Shkodran Mustafi and Granit Xhaka, the latter of whom earned a late redemption after initially struggling in north London. If not for his miraculous turnaround, this could have marked one of the worst summers in their recent history.
What was Lucas Perez's salary at Arsenal?
Given Perez would only spend one year at the Emirates, returning to Spain on loan before that aforementioned permanent switch to the Hammers, what he took from the club with regard to his salary was not as high as it could have been.
After all, the former Elche dud was initially handed a four-year contract, which he fortunately did not see out.
Despite that, his sole year in north London still saw him pocket £3.1m from his £60k-per-week deal, bringing the total fee spent for his one miserable season at the club up to £20.2m.
Did Lucas Perez deserve to earn £60k-per-week?
Given what he offered, it would be hard to argue that Perez deserved anywhere near what he received for his time at Arsenal.
He would join, fail to score and lead the line with consistency, see his opportunities dwindle and then attack the club and its manager before forcing a move to a London rival. In fact, given the total expenditure KSE spent on him, compared with the number of goals he scored, he ended up costing the club £2.8m per strike.
Therefore, it would be crazy to suggest that the striker was anything less than a resounding failure, up there with some of the most bizarre pieces of business in the club's history.