The 23-year-old signed a contract extension at Atletico Madrid, running until 2027, before making the switch to Stamford Bridge. Both Manchester United and Arsenal showed initial interest in the Portugal international, but it is Chelsea who reportedly most appealed to the player.
Standard Sport understands Chelsea have agreed to take on Felix's full wages for the duration of his stay along with paying a sizeable loan fee, with the deal totalling around £16million, a cost United were unwilling to pay.
Chelsea have been on the lookout for attacking reinforcement this month and Felix is their fourth January signing, though the first one expected to immediately compete for a first-team spot, after Benoit Badiashile, David Datro Fofana and Andrey Santos.
Felix has been at Atletico since 2019, arriving from Benfica in a deal worth a staggering £113million to become the fourth most-expensive signing in football history.