Brighton has triggered a £40m release clause in Leeds forward Georginio Rutter's contract.
Leeds signed Rutter in January of last year on a five-and-a-half-year contract from Hoffenheim for a club-record deal, which could rise to £35m.
Rutter played 28 minutes in Wednesday night's 3-0 Carabao Cup defeat against Middlesbrough at Elland Road.
The 22-year-old scored eight goals and assisted 16 in a total of 51 appearances last season as Leeds missed out on an immediate Premier League return after relegation.
The Frenchman's departure would be another major loss for Leeds who have lost Archie Gray and Crysencio Summerville to Tottenham and West Ham respectively.
TrendingRutter could become Brighton's sixth summer signing as new boss Fabian Hurzeler prepares for his first campaign in charge.
Brighton on Wednesday announced the signing of 20-year-old Brajan Gruda from Bundesliga side Mainz in a £25m deal.
Gruda joined Yankuba Minteh, Mats Wieffer, Ibrahim Osman, Malick Junior Yalcouyé and Amario Cozier-Duberry on the south coast.
On Gruda, Hurzeler said: "I'm really pleased to get the opportunity to work with Brajan. I saw the big impact he made last season in the Bundesliga and he's a player I admire a lot.
"The Premier League will be a different challenge but I'm looking forward to working with Brajan and helping to develop his big potential."