Borussia Dortmund are edging closer to the €25m signing of Mainz 05 defender Abdou Diallo, their fifth signing of the summer, according to reports in Germany.

The 22-year-old has been attracting a lot of interest from clubs across Europe this summer following a breakout season in the Bundesliga, as well as fellow defenders Çağlar Söyüncü (Freiburg) and Benjamin Pavard (Stuttgart).


But Diallo looks set to stay in Germany next season after Mainz agreed to sell the defender to Borussia Dortmund for a club record fee - previously set at €17.5m when they sold Jhon Córdoba to FC Köln last year.

A report from Bild outlines that the defender will sign a five-year contract with Dortmund, which will be officially announced at some point over the next week. Diallo has already stopped training with Mainz, with his last session taking place on Saturday.

Mainz director Rouven Schröder confirmed on Sunday that they have held "very good" talks with Dortmund, adding that a "speedy agreement" is expected to be reached this week.

Diallo's arrival at the club will pave the way for Sokratis Papastathopoulos to secure his long-awaited departure, with the Greece international tipped to join former teammates Pierre-Emerick Aubameyang and Henrikh Mkhitaryan at Arsenal.

Borussia Dortmund have already been busy during the transfer window. Thier first task of the summer was to replace manager Peter Stöger, opting to appoint OGC Nice boss Lucien Favre ahead of the new season.


The German outfit have also brought four new players to the club. Goalkeepers Marwin Hitz and Eric Oelschlägel have joined on free transfers this summer, while Dortmund also signed Marius Wolf (€5m) and Thomas Delaney (€20m) from two of their Bundesliga rivals.