#3 Alexandre Lacazette
Arsenal broke their transfer record when they secured the signing of French striker, Alexander Lacazette in the summer of 2017. The Gunners splashed £46.5 million to acquire the services of the France International, making him the most expensive player in the club's history at that time.
The price tag meant that there were lots of expectations in front of the 26-year-old at the Emirates Stadium. Lacazette had a promising start to his Arsenal career, scoring a brilliant goal in his debut match.
He continued with his nice displays in his first few matches. However, the former Lyon striker started declining as time went on, producing average displays and getting limited game time.
What was expected to be a brilliant season for the superstar turned out sour. He could only manage 17 goals and 4 assists in 38 appearances for the Gunners in all competitions during the campaign.