David Datro Fofana is set to leave Chelsea after agreeing terms with AEK Athens.
The deal will be a loan initially, with the Greek club possessing an option to complete a permanent transfer for £20m next summer.
The move is subject to final paperwork being signed between the clubs.
The transfer window is shut in England but Greek clubs can sign players until Wednesday, allowing the Blues to trim their squad further amid unrest internally between the owners Todd Boehly and Clearlake.
After paying Norwegian club Molde £8.4m for the Ivory Coast forward in 2023, Chelsea look set to part ways with the player and could secure a profit should he impress enough this term.
The 21-year-old has appeared just four times for Chelsea and has failed to register a goal.
Fofana was sent out on loan twice, initially with Bundesliga side Union Berlin, where he scored twice in 17 games.
He then joined the Clarets, where he scored four goals in 15 matches.
Chelsea have been attempting to balance their squad in recent weeks with a number of exits including Raheem Sterling, Conor Gallagher, Tino Anjorin, Armando Broja, Trevoh Chalobah and Djorde Petrovic.
Ian Maatsen, Lewis Hall, Romelu Lukaku, Omari Hutchinson and Angelo also departed this summer, helping the club fall in line with Profit and Sustainability Rules.
After a promising performance with a Premier League victory at Wolves, Chelsea were held at home to Crystal Palace.
Now Enzo Maresca’s side travel to Bournemouth this weekend following the international break.