Arsenal have just confirmed the sale of Gabriel Martinelli to Al Hilal, with the transfer fee potentially reaching £60 million. After the deal is completed, the Gunners will have a gap in their attacking depth, while the winter transfer window will not reopen until January next year.
At the end of this frustrating summer window, Arsenal's attacking strength can be said to be weaker than last season — an area already widely considered the team's weakness despite them eventually winning the Premier League title. According to BBC Sport, Martinelli's transfer fee could reach £60 million, highlighting Arsenal's previous decision to refuse to pay £65 million to sign Antoine Semenyo.

The market landscape has changed dramatically
Since then, the transfer market has exploded. Players of a similar level, such as Morgan Rogers and Bradley Barcola, have moved for fees close to double Semenyo's previous price. Therefore, the £60 million raised from selling Martinelli may now not be enough to buy a replacement of the same level.
However, if Arsenal had paid Semenyo's £65 million release clause at the time (as reported by BBC Sport then), and sold Martinelli a few months later, they could have significantly upgraded the left side of their attack at a net cost of only £5 million.
Semenyo was originally a Gunners supporter
Semenyo was in excellent form for Bournemouth in the first half of last season and has continued to shine since moving to Manchester City. The Ghana international scored 10 goals for the Cherries last season and added 11 more after joining Manchester City, giving him 21 goals in total, matching Arsenal forward Viktor Gyokeres' final goal tally across all competitions.
According to The Athletic, Semenyo himself is an Arsenal supporter. It is difficult to understand why Arsenal did not move to sign him. talkSPORT reported at the time that Arsenal were indeed considering Semenyo, but wanted to complete sales before making new signings, with financial restrictions perhaps limiting their options.
However, reports later suggested that Arsenal actually had the financial ability this summer to pursue top players such as Vinicius and Julian Alvarez, making the earlier explanation difficult to reconcile.
Lesson: The transfer market requires more decisiveness
The lesson for Arsenal from this situation is clear: they must act faster and be more decisive in the transfer market. Although waiting for player sales to be completed before making moves has some logic, the North London club appears to have made the wrong choice, and this decision could cost them more in the long term.
A similar situation occurred with Rogers' transfer — Arsenal hesitated and allowed Chelsea to move ahead of them. They are now forced to urgently search for reinforcements in an inflated market.
Looking back just a few months later, signing Semenyo for £65 million would have been an excellent deal — he is already a world-class player. Considering that Arsenal ultimately sold Martinelli in the same year, the decision can be viewed as disastrous: they could have obtained an ideal replacement and upgrade at a net cost of only £5 million.
Of course, hindsight is always easier, but if Arsenal do not learn from this experience, they may repeat similar mistakes in the transfer market in the future.