Amad expressed his fury after Manchester United were beaten 2-0 by Atletico Madrid in the Champions League on Tuesday night, posting "I have no words" and "f***ing disgrace" on his verified Snapchat account.
The 24-year-old started the match on the bench in Madrid and came on for Marcus Rashford in the second half. Less than 10 minutes later, Leny Yoro was sent off. United were already 1-0 down at that point, before Ademola Lookman scored Atletico's second goal to seal the victory.
Martinez hits out after defeat
Amad's comments came after Lisandro Martinez voiced his frustration in a post-match interview. "I have to control myself a lot. But sometimes it's a reflection of how our club is at the moment, you know?" he said.
"We (had) a fantastic season last season, and now we expect more from the top, from above, you know, to bring more players to compete, because many, many teams bring many players in as well. Today also, Atletico have an amazing team, and they deserved to win today. I expected more, honestly. I expected more."
Carrick responds to criticism
Martinez then turned his attention to director of football Jason Wilcox. "I expected more from our technical director," he said. "I have to be honest, you know? And also, as players, we have to do more, but it's also important when you make a strong squad to be ready for these kinds of nights."
Asked about manager Michael Carrick, Martinez added: "He does his best. But every season is different. You cannot say what you did last season. The teams know how you play, the teams know every detail, you know? And if you don't change, next season is a big problem. You cannot keep changing managers. What about other areas? I can't say more."
In his post-match press conference, Carrick said of Martinez's comments: "I need to find out a bit more about it before I can say if and what is going to be done. I really can't comment any further because I haven't seen it."