Arsenal's quest for an unprecedented quadruple has crumbled, but is their famously solid defense showing cracks too? The Premier League leaders saw their four-front battle halved just before their crucial Champions League clash with Sporting CP, raising questions about their resilience.

Those concerns seemed validated from the opening whistle in Portugal. Sporting came out swinging, rattling the crossbar and forcing David Raya into action multiple times within the first ten minutes—a remarkable and rare breach of Mikel Arteta's typically impenetrable backline.

This shaky start is a notable shift for a team that has built its title charge on defensive discipline. For a squad and its supporters who pride themselves on a strong, unified defense, these early lapses will be a worrying trend to monitor as the pressure of the title race intensifies.