In the long arc of football's recurring lesson — that spending cannot substitute for coherence — Chelsea's 2-1 defeat to Arsenal on Sunday offered a quietly damning illustration. Despite investing £349m in a summer of reconstruction, manager Xabi Alonso found himself fielding two right-backs in central midfield as injuries and failed transfers converged into a single, visible vulnerability. The absence of Moises Caicedo, returned too soon and now sidelined indefinitely, has stripped away the illusion of depth, leaving a club that looks formidable in attack but exposed in the engine room where