Brighton have agreed an original £7.5m price that could rise to £10m to sign Billy Gilmour from Chelsea.
The Scotland midfielder, 21, put in previous season on loan at Norwich City and has not featured for the Blues this season.
The previous Rangers youth participant was an unused substitute for Chelsea in both of those the FA Cup and Champions League finals in 2021.
Gilmour is the 2nd Chelsea participant to be part of Brighton this summertime, immediately after Levi Colwill signed on loan in August.
In June, Gilmour prolonged his Chelsea contract to 2024 but leaves Stamford Bridge having created 21 appearances for the club.
Gilmour, who has received 15 caps for Scotland and was their stand-out player from England in the European Championships last 12 months, impressed early in his Chelsea job.
Nonetheless, he slipped down the pecking get under supervisor Thomas Tuchel and endured a difficult time on loan at relegated Norwich past time period.
Meanhwile striker Florin Andone, who scored 6 goals in 30 appearances following signing up for Brighton in 2018, has experienced his deal terminated by mutual consent.
