Arsenal has signed some brilliant players down the years but just like all clubs, they've made a couple of blunders in the transfer market. We've picked out five that didn't quite live up to the hype or price-tag.
Pound-for-pound, here are five of the worst.
Francis Jeffers - £8m (Everton)
Englishman Jeffers was signed from Everton in 2001 for £8, which was a large sum of money 18 years ago. He never realised his potential as Arsenal's new "Fox in the box" and started a string of players that didn't perform in the Gunners number 9 jersey. Jeffers realised that he just wasn't good enough to claim a place in the first team ahead of Thierry Henry, Dennis Bergkamp, Nwankwo Kanu & Sylvain Wiltord.
He managed just 39 appearances across a four-year spell, scoring eight times. Not such a fox in the box after all.
Shkodran Mustafi - £35m (Valencia)
It may seem unfair to include a current player in this list, but large sections of Arsenal fans have had enough of the error-prone German defender. Once a winner of the World Cup in 2018 and a rock at the back for Valencia, Mustafi now looks jittery against most opponents, and his error that cost Arsenal against Crystal Palace on the weekend might be the last straw for Emery and the fans.
Gervinho - £10.8m (Lille)
Once upon a time, the Ivorian formed a deadly duo with Eden Hazard in France and when rumours that Arsene Wenger was interested surfaced, supporters grew excited at the prospect of a flamboyant winger signing on at The Emirates. Gervinho managed only 11 goals in 69 appearances during a tricky spell at the club, and he moved to Roma. The 31-year-old has shown a resurgence this season with 10 goals and two assists in 25 appearances for Parma in Serie A.
Cruelly, many Arsenal fans will remember Gervinho for THAT miss against Bradford in the FA Cup.
Sebastien Squillaci - £4m (Sevilla)
Shkodran Mustafi isn't the only defender Arsenal has signed from LaLiga that has underperformed for the club. Frenchman Squillaci was expected to bring experience and know-how to a defence that included Johann Djourou and Kieran Gibbs. This Arsenal side only won once in the months of March and April, a sequence that completely ripped apart any title ambitions that they had.
Squillaci was an unused substitute in 2011's League Cup final against Birmingham, a match which Arsenal lost.
Denílson - £4m (São Paulo)
There were high hopes for Denilson when he arrived in North London as a teenager. The central midfielder had captained Brazil U17s in 2005 and was regarded as the next big thing in world football, but things just didn't turn out that way for Denílson Pereira Neves. Now 31, he's at Botafogo after unsuccessful stints back at Sao Paulo, Al-Wahda & Cruzeiro. Controversy seems to have followed Denilson everywhere he went.
Back to the future, Arsenal & Mustafi's next fixture is away to Wolves on Wednesday night as they continue their top-four quest. Will the German be in the side?