Martínez's criticism of Jason Wilcox echoed through Manchester United dressing room

Lisandro Martínez told teammates after Manchester United's 2-0 Champions League defeat at Atlético Madrid on Tuesday that Jason Wilcox was failing as the club's director of football. The defender's view, widely shared in the dressing room, reflects frustration over recruitment and the squad's lack of depth.

The defeat left United with two wins all season. Michael Carrick's side had taken only six points from their first six Premier League matches, their poorest league start for 40 years, and that run of form has placed Carrick's position under pressure.

Martínez addressed the club hierarchy directly in his post-match remarks. “Tonight it is easy to say the coach, easy to say the players but also we have to see other areas,” he said, pointing upwards. “I expect more [investment], 100%. I expect more from our technical director [Jason Wilcox]. I have to be honest, as players we have to do more but it is also important when you make a strong squad to be ready for this kind of night.”

Wilcox, the executive in charge of transfers, oversaw a £155m spend in the last window on Youri Tielemans, Andrey Santos and Carlos Baleba. Squad members have questioned why three midfielders were recruited while other positions were not strengthened. Wilcox had targeted a left-back, with Newcastle’s Lewis Hall identified as the prime target.

Luke Shaw remains United's only senior player at left-back and his 12-year career at the club has been plagued by injury. The 31-year-old missed the Atlético defeat and Saturday's 1-1 draw with Tottenham owing to a muscular problem. Players view the lack of cover at left-back as evidence that Carrick has been left without the resources to challenge.

United were eliminated from the Carabao Cup by Brighton after making eight changes. Although Carrick led United to third last season, that finish came after he took over as caretaker in mid-January. He inherited a squad with only 17 league games to play because the team were out of all other competitions.

Martínez is understood to favour a move, ideally to an elite European club outside the Premier League. He is out of contract next summer.