The move is understood to be a personal request from Hansi Flick, who has asked sporting director Deco to get the deal over the line after identifying the 24-year-old as a perfect fit for his system. Adeyemi's contract in Germany runs until 30 June 2027, putting Borussia Dortmund under pressure to sell now rather than risk losing him for nothing in a year's time.
The forward has been on Barcelona's radar in various windows since his time at Salzburg, where his pace first caught wider attention - he forced three penalties in 45 minutes on his Champions League debut against Sevilla in 2021 and, two years later, covered 65 metres in nine seconds during a memorable solo goal against Chelsea.
Adeyemi's path to the top was unconventional. Born in Munich to a Romanian mother and Nigerian father, he joined Bayern Munich's academy in 2010 but left just two years later - officially over discipline issues, though the player has always maintained it was jealousy from other parents.
He rebuilt his career at SpVgg Unterhaching, where president Manfred Schwabl made him study as a condition of playing, before a €3.3m move to Salzburg in 2018 made him Germany's most expensive teenage transfer at the time.
He turned down interest from Chelsea, Atletico Madrid, Liverpool and Barcelona - who reportedly offered up to €15m - to extend at Salzburg in 2020, before a prolific title-winning campaign earned him a €30m switch to Dortmund in 2022 as Erling Haaland's replacement.
Flick, who gave Adeyemi his senior Germany debut against Armenia in 2021 - a match in which the youngster scored the final goal in a 6-0 win - remains a long-standing admirer of the winger's explosive style. Adeyemi has continued to describe his speed as his greatest asset, having been clocked running 30 metres in 3.78 seconds during his time in Austria.
Should the transfer go through, Adeyemi would join a crowded Barcelona forward line already containing Lamine Yamal, Raphinha and this summer's marquee signing Anthony Gordon, with his versatility seen as valuable depth for a team competing on multiple fronts.