Among the options available to Barcelona this summer, Karim Adeyemi seemed like an unlikely signing.The Borussia Dortmund winger and 11-cap Germany international has had a productive four seasons since joining the Bundesliga club from Austria’s Red Bull Salzburg in July 2022, but has never quite delivered on his potential.Adeyemi, 24, is an explosive player and a dangerous counter-attacker, but 23 goals in 98 German top-flight appearances is not, in itself, an overwhelming case for a transfer to one of the biggest clubs in the world.So why has this move happened?The context is important.Adeyemi has joined Barcelona for a guaranteed fee of €22million (£18.8m; $25.2m), with add-ons potentially taking that beyond €30m, depending on performance. Dortmund have also secured a significant sell-on fee as part of the deal.The German club had to sell Adeyemi this summer. He had one year left on his contract and has long intimated he would be unwilling to sign an extension. In fact, he’s been actively seeking a transfer for some time, changing agents on multiple occasions in pursuit of that move.Dortmund will miss Adeyemi.During a period when their talent pool is not as deep as it once was, he was among the club’s most dangerous attacking players, while also being a good fit for coach Niko Kovac’s direct style of football. Nevertheless, as confirmed by chief executive Carsten Cramer this week, Dortmund are aiming to restock the squad with younger players and the kind of appreciating talent they were known for in previous eras.With Adeyemi’s value dwindling because of that contractual situation and transfer business to fund, a sale is logical, even at such a meagre fee.Adeyemi and Dortmund were Champions League runners-up in 2023-24, losing to Real Madrid in the final (Adrian Dennis/AFP via Getty Images)That presented an opportunity for Barcelona, who were made aware of Adeyemi’s availability by Jorge Mendes, his latest agent. Mendes enjoys a close relationship with Joan Laporta, Barcelona’s club president, and represents several of the Spanish champions’ players, including Lamine Yamal, Marc Casado and Alejandro Balde. His influence has obviously been important.In football terms, Adeyemi will help fill the gap left by Marcus Rashford. Barcelona have decided not to make his season-long loan from Manchester United permanent, despite the 28-year-old England international forward contributing 15 goal involvements (eight goals, seven assists) in 35 La Liga appearances.With Adeyemi, they have instead secured a player who is four years younger than Rashford and will possibly be on a more affordable salary. Barcelona believe he will be able to produce a similar statistical output and fulfil a comparable role in their squad.Naturally, this move has hinged on Barca head coach Hansi Flick.