Sky TV reported that the Premier League club offered Leipzig a fixed fee of £90 million plus an additional £10 million in add-ons.
Diomande joined Leipzig in the summer of 2025 from Spanish side Leganes for £20 million, signing a contract until 2030 with no release clause.
The young Ivorian quickly made an impact, attracting the attention of several top clubs. Leipzig, having qualified for the Champions League, aims to retain Diomande's talent, but speculation suggests they might reconsider if offers reach £120 million.
Diomande could further boost his value at the World Cup, where Ivory Coast won their opening match against Ecuador and will face Germany on Saturday. Diomande featured in 33 Bundesliga matches during the 2025/2026 season, scoring 12 goals.