A tribunal decided the Blues must pay a basic fee of £1m rising to a potential £4.25m for striker Shumaira Mheuka, 16, after he moved to Stamford Bridge in July 2022.
Brighton have also been awarded compensation of up to £2.1m for promising left-back Zak Sturge plus another £250,000 if the 19-year-old plays for England.
Londoner Sturge was poached from Brighton by Chelsea last year and spent the first half of the season on loan at Peterborough.
The teenager has so far made 31 appearances for Chelsea’s under-21 side and has been capped by the Three Lions up to under-18 level.
As for Mheuka, he is also an England youth international, along with scoring seven goals in 13 under-18 appearances for the Blues.
Since Todd Boehly took control of Chelsea they have paid Brighton more than £225million for players and staff – more than double what it cost to build the Amex Stadium.
Marc Cucurella, Moises Caicedo and Robert Sanzhez have all made the move from the Seagulls in the last two seasons.
Meanwhile, the Blues swooped for then Brighton boss Graham Potter in September 2022, only to sack him after seven months and just 31 matches.
Along with Potter, coaches Billy Reid, Bjorn Hamberg, Bruno Saltor and Ben Roberts have all made the switch.
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Meanwhile, Chelsea’s chief analyst Kyle Macauley and sporting director Paul Winstanley both joined the club from Brighton.
Sam Jewell, the former head of scouting at the Amex, will become the 11th first-team player or staff member to make the move in November.
He is set to join Chelsea in the same role later this year after leaving Brighton last week.