Emi Martínez underwent surgery after suffering a head injury during Chelsea's Premier League win over Everton on Saturday. The Aston Villa goalkeeper was taken to the hospital for precautionary tests following the incident. Martínez said he expects to return to action in a few weeks, meaning he'll miss the next stretch of Villa fixtures. The timeline puts him back in mid-to-late January at the earliest, assuming no complications from the procedure. Villa's backup keeper will need to step in during his absence. Head injuries always draw scrutiny in modern football, and the club took the right approach with immediate hospitalization and evaluation. This impacts Villa's defensive stability during a crucial period of the season as they push for European qualification.