The 23-year-old is currently representing Portugal at the 2022 World Cup, helping Fernando Santos's side to reach the last-16 stage of the competition.
Felix has found it difficult to make his mark for Atletico during the 2022-23 campaign, though, only managing four goals and three assists in 18 appearances in all competitions.
The Portuguese failed to find the back of the net in five outings in the group stage of the Champions League, with Diego Simeone's side finishing fourth in their section.
Meanwhile, he has only managed three goals and three assists in 12 La Liga appearances during a disappointing start to the campaign.
Felix was on the scoresheet against Almazan in the Copa del Rey before the season was halted for the World Cup, but his relationship with Atletico boss Simeone has allegedly broken down.
A recent report claimed that the forward's agent Jorge Mendes has been in touch with Man United to offer the club the chance to sign his client in January.
The Red Devils are expected to be in the market for a new attacker in the middle of the campaign, having terminated Cristiano Ronaldo's contract.
According to journalist Dean Jones, Felix is open to moving to the Premier League, and Chelsea are likely to join Man United in pursuit of the forward.
"I've been told before that he is open to coming to the Premier League as his next destination. As soon as that decision is made - if it's made - then I think clubs like Chelsea will be having a look," Jones told GIVEMESPORT.
Felix has scored 33 goals and registered 18 assists in 129 appearances for his Spanish side in all competitions.
The forward has a contract at Wanda Metropolitano until June 2026, but there have been claims that he will be available for around £85m during the winter market.
Bayern Munich and Paris Saint-Germain have also been credited with an interest in the former Benfica youngster, although it is thought that he is prioritising a switch to the Premier League.