Manchester United's hierarchy is investigating comments Lisandro Martínez made following the 2-0 Champions League loss to Atletico Madrid. The club hasn't ruled out disciplinary action against the Argentina center-back, sources told ESPN.

Martínez subsequently released a statement addressing his remarks, though the full context of what he said remains unclear from the reporting. United's decision on whether to sanction him depends on their assessment of those initial comments and his follow-up statement.

This falls into a familiar pattern at Old Trafford. Player discipline and locker room management have been recurring storylines under Erik ten Hag. The Atletico result itself was damaging enough, a home defeat in Europe that leaves United's Champions League campaign in precarious shape. Adding internal friction only compounds the problem.

The club will weigh the severity of Martínez's words before acting. Release a harsh statement and he looks like he's undermining the manager. Do nothing and it sends a message that accountability doesn't matter. Ten Hag's handling of this situation will tell us plenty about his control of the dressing room right now.