The Argentina international first made headlines after questioning the club’s transfer policy and singling out director of football Jason Wilcox following Tuesday’s defeat. He then reiterated his concerns during an interview with former United goalkeeper Peter Schmeichel.
Martínez argued that Michael Carrick could not be expected to solve every problem without sufficient backing from the club’s decision-makers.
“You can’t keep changing, changing, changing the manager. What about other areas? I can’t say more,” he said.
The defender also called for greater investment in the squad, pointing to the need for more players capable of competing at the highest level.
“I expect more. One hundred per cent. I expect more from our technical director,” Martínez said in his earlier interview.
He acknowledged that players and the manager must accept responsibility when performances fall short, but insisted that the club’s leadership should face scrutiny as well.
“When you watch the games on television, you see the players and the manager and you point the finger, which is right, we take the responsibility. But also, as a club, I expect more, you know?
“I expect more. I’m not going to close my mouth.”
Martínez believes United must be more ambitious about their objectives, rather than simply concentrating on short-term results.
“We need more ambition. We need to talk more about winning the Champions League and winning the Premier League.
“If we don’t say the truth, nothing will change.”
His comments followed a difficult night in Madrid. United conceded to Pablo Barrios inside the opening minute and struggled to find an equaliser before Leny Yoro was sent off in the second half. Atlético then took advantage of their numerical superiority, with Ademola Lookman scoring the second goal.
Martínez also criticised aspects of United’s performance, including their body language and failure to take chances against elite opposition.
“We are not playing well as a team.
“The body language; we miss three or four chances and we are negative.
“When you play against these teams, especially in the Champions League, you can’t miss opportunities and you can’t concede in the first minute.”
The defender added that United needed to rotate their players across a demanding schedule but did not believe the squad compared favourably with those of their principal rivals.
“We have many games, we have to rotate players, and for me we don’t have the best squad compared to other top teams.”
Martínez’s intervention has intensified scrutiny of Manchester United’s recruitment strategy and the relationship between the squad and the club’s hierarchy.
With a domestic meeting against Leeds approaching, Carrick must now find a way to improve results while the debate over the club’s direction continues.