Gonzalo Higuain was not included in Milan's squad for their game against Genoa as a move to Chelsea nears.
Milan decided to leave him out for Monday's game as they wait for his move to the Premier League to be completed.
The Argentine forward, who joined Milan last summer on loan from Juventus in exchange for 18 million euros plus an option to buy for 36 million euros, is expected to move to England, according to Italian media reports.
Depending on how he does in London, an initial six-month loan could be extended until June 2020.
Chelsea are looking to sign a striker with Alvaro Morata set to join Atletico Madrid.