Borussia Dortmund has signed Carney Chukwuemeka, an England youth international, from Chelsea on a five-year contract.
The 21-year-old spent the second half of last season on loan at the German club and joins in a transfer that might cost around £24 million.
The offensive midfielder made 32 appearances for Chelsea after joining from Aston Villa for £20 million in 2022.
Blues defender Aaron Anselmino has also agreed to join Dortmund on a season-long loan and has flown to Germany to complete the transfer.
The Chukwuemeka signing ensures Chelsea’s player sales revenue this summer exceeds £270 million, nearly matching the £277 million spent on incoming transfers.
European football’s governing body Uefa has told the Blues they must record a positive transfer balance this window in order to be allowed to register their new signings for this season’s Champions League.
It follows them having been fined £26.7m for a breach of Uefa’s football earning rules and having had a squad cost ratio – the proportion of their income paid out in wages – above 80%.
A number of other players have been linked with a move away from Stamford Bridge before Monday’s transfer deadline, including forwards Nicolas Jackson, Christopher Nkunku and Tyrique George, winger Raheem Sterling and defender Ben Chilwell.
Chelsea could also bring more players in, with Manchester United winger Alejandro Garnacho and RB Leipzig midfielder Xavi Simons among those linked.