The Blues have been linked with a free transfer move for the Belgian international in 2023 as part of an attempt to reunite him with Graham Potter at Stamford Bridge.
Trossard has hinted at his potential interest in making the move to the Premier League giants due to his ambition to play Champions League football.
The 27-year-old has enjoyed a strong start to the 2022/23 campaign, with five goals already for the Seagulls, and he is expected to join the Belgium squad for the 2022 World Cup in Qatar.
As per reports from the Daily Mirror, Chelsea remain as favourites to secure a deal for the former Genk star, but Atletico are monitoring the situation with growing interest.
Trossard has so far declined to sign an extension beyond the end of the season and he can negotiate with a non-English side from January.