RB Leipzig has a strong possibility of signing Kaishu Sano from FSV Mainz 05, with a potential transfer fee of 50 to 60 million euros under discussion for the 25-year-old Japanese defensive midfielder. Several clubs in the Premier League are also interested in the player. However, Mainz 05 wishes to avoid a sale late in the transfer window. 'Bild' reports that sporting director Christian Heidel has set an internal deadline of approximately August 27th for any potential deal, to allow time to find a replacement. Heidel also publicly told 'Bild' that Sano will not be sold on August 31st. He acknowledged that an offer could be made that they cannot refuse, but stated the club is financially able to retain the player and would be happy if he remained. Sano, who joined Mainz in July 2024, has a contract until 2028. He has 16 caps and one goal for Japan, and his current Transfermarkt market value is €50.00m.