Yet Herrera insisted Mourinho's combative approach is what the players need and described his battle to sign more players this summer as a normal one between a manager and his employers.
"More or less I know (my best team)", the United boss told beIN SPORTS.
"I am confident I get one, but I think two I am not going to get which is not a drama". So, I think we have fantastic players, but, of course, always managers want to improve their teams, but it's not my business. "You want to fight for the titles but you don't have the team with you to work for it right now".
"But then club decisions are different and normally you don't get what you want, which happened basically during all my career".
The 55-year-old manager took a dig at the transfer board as well as his players' performances in MI on Saturday and stated in a press conference, "The atmosphere was good but if I was them I wouldn't have come, I wouldn't have spent my money to watch these two teams".
Ironically one of those targets is Leicester's England centre-back Harry Maguire, though the 2016 champions' wealthy Thai owners feel they do not have to sell, particularly having accrued a club record £60 million ($79 million) for the sale of Riyad Mahrez to Manchester City. For example, we played against Liverpool and they had maybe 80 percent of their squad ready, Milan maybe 90 percent of their squad.
"The positive feeling is to win the first Premier League match", Mourinho said before the match.More news: Swing-voter Rand Paul: I'll vote for Kavanaugh on Supreme Court
Get the latest World Cup news updates.
"The players that we have bought one is a goalkeeper cover, another one is a 19-year-old kid".
Mourinho is still without a number of players, who reached the latter stages in Russian Federation, and made clear his preference that they cut their breaks early to aid preparations for the season opener against Leicester on August 10.
"The Premier League could and should do that".
"I agree totally with the window closing at the same time the Premier League starts".
Bookmakers are now taking bets on Mourinho becoming the first Premier League manager to be sacked or leave his post this season.
"You look at other countries with lots of players in the World Cup they start later - Spain and Italy starts later".