Arsenal enjoyed a particularly busy transfer window this summer, with Edu adding five fresh faces to Mikel Arteta's first-team squad, while the Brazilian also moved six players out of the club on permanent deals, as well as a further six on season-long loans.

And, while it would be difficult to argue that the technical director was not successful in his summer dealings - with marquee signing Gabriel Jesus on fire in front of goal, as well as the Gunners currently sitting top of the Premier League table - there is a case to be made that Edu's decision to cash in on Konstantinos Mavropanos has already proven a mistake.

Indeed, after failing to cement a spot in Arteta's first-team squad following his £1.8m move from PAS Giannina back in 2018 - making a total of just eight senior appearances for the Gunners - the centre-back was shipped out on loan to VfB Stuttgart last season, a €500k (£415k) deal that reportedly included a €3m (£2.5m) option to buy clause for the German side.

However, considering just how impressive the 24-year-old was for Die Roten last time out, Edu's decision to include such a cheap purchase option in the defender's temporary switch to southwest Germany immediately looked to have been something of a shocker by the Brazilian.

Indeed, over his 31 Bundesliga appearances in 2021/22, the £17.5m-rated talent was in imperious form at the back, helping his side keep two clean sheets, in addition to making an average of 2.2 interceptions, 1.8 tackles, 5.4 clearances and winning 6.0 duels - at a success rate of 67% - per game.

The Greece international also impressed going forwards, scoring four goals, as well as taking an average of 1.1 shots, completing 43.6 passes - at a success rate of 80% - and finding his man with 6.1 long balls per fixture.

These returns saw the player who Ian Wright once dubbed "fearless" average a simply sensational SofaScore match rating of 7.13, ranking him as Stuttgart's third-best performer in the top flight of German football last season - playing a key role in helping his club avoid relegation from the division.

Rather unsurprisingly, this level of performance saw the German side activate the defender's nominal £2.5m purchase option, and Mavropanos has continued to make Edu's decision to include such a clause something of a shocker so far this season.

Indeed, over his ten league outings in 2022/23, the £13k-per-week centre-back has once again been in exceptional form, scoring one goal, registering one assist and helping his side keep one clean sheet, in addition to making an average of 2.3 tackles, 2.0 interceptions, 3.9 clearances and winning 6.2 duels - at a success rate of 65% - per game.

These metrics have seen the 15-cap international average a breathtaking SofaScore match rating of 7.42, not only ranking him as Michael Wimmer's best performer in the Bundesliga but also as the seventh-best defender in the league as a whole.

As such, considering his astonishing returns in Germany and the fact the 24-year-old now boasts a market valuation that is 600% greater than the fee Arsenal sold him for this summer, it is clear for all to see that Edu well and truly had a nightmare when agreeing a £2.5m option to buy clause in Mavropanos' loan to Stuttgart last season.