Dembele was not in the Lyon squad that drew 2-2 with Stade Rennes on Saturday night as he continues his recovery from a broken arm suffered in training in December.
The 24-year-old Frenchman joined Lyon from Celtic in the summer of 2018 and has scored 32 top flight goals in 76 appearances in his time at the club.
But with just a solitary goal from 16 appearances for Lyon in the 2020/2021 season, Dembele looks disenchanted at the Groupama stadium and is looking for a way out.
Atletico are in the market for a new frontman to aid their title push after parting ways with Diego Costa last month, leaving Luis Suarez as their only senior striker.
"Moussa came to see me, he thinks that this is the moment to change teams, that he has lost a bit of motivation,” Lyon sporting director Juninho told Telefoot after the Rennes game.
“This was not something we foresaw, I like him a lot.
“Keeping someone who does not really want to keep up the intensity through the next five months, that is not ideal.
“We are in talks with Atletico, I think that Moussa has found an agreement with Atletico.”
Lyon will need to find a replacement if Dembele leaves as they lead the Ligue 1 standings by a point.
