The Argentina international questioned the club’s summer recruitment and called for greater investment after the loss. In a subsequent social media statement, he stopped short of apologising but reaffirmed his desire to see United competing for major honours.
“After the match, I spoke out of anger and frustration at not getting the result we all wanted,” he wrote.
“Those who know me know how I live football, with passion, commitment and a huge desire to win. And when things don't go our way, it hurts, especially when representing a club with the history and stature of Manchester United.
“My words reflect how I feel and how much I want to see this club competing for the biggest honours.
“Those high standards are part of how I see football and the responsibility that comes with wearing this shirt.
“When I talk about wanting more, I'm talking about the ambition we must all have as part of this club.
“To keep growing, to become stronger and to have everything we need to compete at the highest level.
“These are standards we must all hold ourselves to, starting with me.”
Martínez also accepted that the players must take responsibility for changing United’s fortunes.
“I know that, first and foremost, it's us, the players, who have to deliver, and I put myself at the front of that responsibility.
“We need to demand even more of ourselves and work together to take Manchester United back to the top.
“I believe in my team-mates, our manager [Michael Carrick] and everyone working to help this club move forward.
“I'm convinced that the way forward is to keep working together, with ambition and commitment.
“My goal has been the same since day one, to win, compete at the highest level and to give everything I have for this badge.”
His original post-match comments were more confrontational. Martínez challenged the club’s recruitment strategy and defended Carrick, saying: “You can’t keep changing, changing, changing the manager. What about other areas? I can’t say more.”
He specifically demanded more from director of football Jason Wilcox.
“I expect more [investment]. One hundred per cent. I expect more from our technical director.”
Martínez also criticised the team’s performance, pointing to its body language and failure to take chances.
“We are not playing well as a team. The body language; we miss three or four chances and we are negative.”
He argued that United needed greater squad depth to cope with a demanding schedule.
“We have many games, we have to rotate players, and for me we don’t have the best squad compared to other top teams.”
Manchester United have struggled for consistency this season, increasing scrutiny of the club’s recruitment and leadership. Martínez’s contract expires at the end of the campaign, although United have the option to extend it by another year.
His latest statement seeks to make clear that his criticism came from a desire to see the club succeed, rather than a lack of belief in the people working there.