Romelu Lukaku’s strong performances at Everton during his loan spell have significantly boosted his market value and appeal across Europe. Atlético Madrid’s interest makes strategic sense—Diego Costa was nearing a likely departure (eventually to Chelsea), and Lukaku, with his physicality, finishing ability, and Premier League experience, fits well into Diego Simeone’s system of fast transitions and aggressive pressing.
For Chelsea, selling Lukaku (especially to a club not in direct competition) could make financial and sporting sense, particularly as Mourinho didn’t appear to have long-term plans for him. Meanwhile, Atlético would be securing a young, proven goalscorer with room to grow.