Bundesliga
Bayer Leverkusen have been the undisputed engine room of this summer's transfer window, and the scale of their business is striking. The headline arrival is Miguel Gutiérrez, who joined from Napoli on 4 August in a confirmed transfer. Leverkusen also brought in Facundo Medina from Marseille around the same time, adding further depth to their squad. Earlier in the window, Luca Erlein arrived from 1899 Hoffenheim on a permanent basis — though he was almost immediately sent out on loan to Energie Cottbus, suggesting he is being developed rather than integrated into the first-team picture straight away. The overall pattern at Leverkusen is one of aggressive squad reshaping: recruiting in areas of need while systematically trimming the roster through a combination of permanent sales and loans.
Serie A
Juventus were among the beneficiaries of Leverkusen's clearout, securing the permanent transfer of Kerim-Sam Alajbegović from the German club at the turn of August. The deal, confirmed as a transfer, saw Kerim-Sam Alajbegović move from Bayer Leverkusen to Juventus. Napoli, meanwhile, let Miguel Gutiérrez leave on a permanent basis, continuing what appears to be a period of squad transition.
Ligue 1
Marseille parted ways with Facundo Medina in a permanent transfer to Leverkusen — a departure that points to ongoing rebuilding. Lorient received the loan of Noah Mbamba from Bayer Leverkusen on 7 August. Loans of this type from a club of Leverkusen's standing can be genuinely impactful for a side with Lorient's resources.
La Liga
Two Spanish clubs picked up players from the Leverkusen exodus. Abdoulaye Faye joined Celta Vigo on loan from Bayer Leverkusen on 2 August. Alejo Sarco joined Sporting Gijón on a permanent transfer from Bayer Leverkusen in July.
Eredivisie
AZ Alkmaar completed the permanent signing of Andrea Natali from Leverkusen in late July, rounding out a busy spell of Dutch business.
Whether this represents a squad that is becoming leaner and more focused — or one still searching for its final shape — will become clearer as the season progresses.