Chelsea is set to accelerate its efforts to sign a new central defender during the current January transfer window, a strategic shift aimed at strengthening the squad under newly appointed head coach Liam Rosenior. Rosenior took over as Chelsea's manager on January 6, 2026, or January 8, 2026, replacing Enzo Maresca, who was dismissed after a period of inconsistent results. The decision to fast-track a defensive signing, initially planned for the summer, stems from a perceived need to reinforce the backline, particularly following Levi Colwill's season-ending injury and other defensive vulnerabilities observed during the season. According to reports from The Telegraph and corroborated by numerous sports news outlets, Chelsea aims to provide Rosenior with immediate reinforcements to navigate a busy fixture schedule and implement his tactical vision. Among the players being closely monitored by Chelsea are Rennes centre-back Jeremy Jacquet and Como's Jacobo Ramón, formerly of Real Madrid. Additionally, Sporting CP's Ousmane Diomande remains a long-standing target for the club, with Chelsea reportedly exploring options to negotiate his release clause. This aggressive approach in the transfer market marks a departure from earlier expectations of a quiet January window for the London club.