The USA international only touched down at Elland Road last summer but was unable to prevent the Whites from sliding back down into the Championship for the 2023-24 season.
As a result, Adams has been expected to depart Leeds after just one season at the club, following a mass exodus of players out of the Elland Road exit door in the summer window.
While Adams remains under contract with Daniel Farke's side for another four years, his terms reportedly include a clause allowing him to depart for a mere £20m following the Whites' relegation.
Chelsea were reported to be considering activating that option last week, and according to Sky Sports News, the Blues have now triggered the 24-year-old's release clause.
The report adds that Adams is now set to undergo his Chelsea medical within the next 24 hours, as the former RB Leipzig man prepares to reinforce the Blues' depleted midfield ranks.
Adams will leave Leeds having failed to provide a goal or assist in 26 matches in all tournaments, starting 24 Premier League games last term before sustaining a season-ending hamstring injury.
The American was nowhere to be seen during Leeds' opening 2-2 Championship draw with Cardiff or EFL Cup win over Shrewsbury Town on Wednesday as he continues his recovery, although Farke revealed last week that he was closing in on a return to training.
Whether Adams will be fit for Sunday's Premier League opener against Liverpool remains to be seen, but the 24-year-old is not expected to be the last midfielder through the door at Stamford Bridge this summer.
The Blues have lost all of N'Golo Kante, Ethan Ampadu, Mateo Kovacic, Mason Mount, Ruben Loftus-Cheek and Tiemoue Bakayoko this summer, while also allowing Jorginho to join Arsenal on deadline day in January.
However, Lesley Ugochukwu represents Chelsea's only midfield incoming so far, joining Robert Sanchez, Angelo Gabriel, Diego Moreira, Christopher Nkunku, Nicolas Jackson and Axel Disasi on the new arrivals list.
Ugochukwu is expected to join Chelsea's sister club Strasbourg on loan for the 2023-24 season, though, leaving Enzo Fernandez, Conor Gallagher, Carney Chukwuemeka, Cesare Casadei and Andrey Santos to battle for midfield minutes.
Casadei is expected to join Leicester City on loan in the coming days, though, and Chelsea are still working on potential deals for Brighton & Hove Albion's Moises Caicedo and Southampton's Romeo Lavia.
A £48m bid has allegedly been tabled for Lavia, who is also on Liverpool's wanted list, but Southampton are holding out for £50m to let the Belgian starlet leave this summer.
Meanwhile, Chelsea have already failed with an £80m bid for Caicedo, but the Blues supposedly want to seal the signing of the Ecuador international before their Premier League opener on Sunday.