The Atletico Madrid striker, who previously had a loan spell at Chelsea in the 2022-2023 season, is now set to return to England.
Per The Mail, Chelsea hope the offer will be sufficient to convince Atletico Madrid to sell.
The Spanish club will then be committed to purchasing Conor Gallagher from the Blues.
Initially, the deal involved young Atleti forward Samu Omorodion moving to Chelsea.
However, the Blues rejected that move when Omorodion had an issue in his medical.