Jose Mourinho faces disciplinary action from the FA, and an almost definite touchline suspension, after being sent to the stands by referee Jon Moss during a 1-1 Premier League home draw with West Ham.
In late October, he was suspended for one game, and fined 8,000 pounds (9,400 euros/$10,000), for an altercation with referee Mark Clattenburg during a draw with Burnley.
That incident followed a 50,000-pound punishment for comments made about the decision to allow referee Anthony Taylor to officiate the game with Liverpool.
The latest flashpoint also involved a referee with whom Mourinho has recent history.
Last season, while in charge of Chelsea, Mourinho had an altercation with the same official in a game at West Ham which resulted in a one-match stadium ban for the Portuguese.
A year on, against the same opposition and with the same referee, Mourinho kicked a water bottle fully 20 yards to protest Taylor?s decision to caution Paul Pogba for simulation after 27 minutes, a card that rules the French international out of United?s League Cup quarter-final tie -- again with West Ham -- at Old Trafford on Wednesday.
"I think everyone saw his frustration was shown in that situation," said assistant manager Rui Faria after Mourinho refused to speak post-match.
"It should have been a free-kick for us and it ended with a yellow card for Paul and he is out of our next match.
"So there are maybe reasons to express some frustration. After that, things that are part of the game and the referee took a decision.
"But I think everything comes from a decision that should be the opposite way."
By that stage Zlatan Ibrahimovic had equalised an early opening goal from Diafra Sakho.
But, as has been the norm recently, Mourinho?s team could not find a winner as they recorded a fourth consecutive home league draw -- the first time since 1990 they have gone four home games without victory.
More worrying yet, United have now recorded their worst start to a season, after 13 games, since 1989-90, the season that saw Sir Alex Ferguson famously win the FA Cup after surviving strenuous calls for his dismissal from supporters.
"We were the best team on the pitch," said Faria. "We didn't have any tactical issues during the game. Defensively we were very compact. Offensively we created the chances to win.
"We are showing that as a team we are a strong side and we can do very good things. We create chances that in a normal way should be goals and the game should be in a comfortable way.
"It is not happening. We get frustrated. The only thing we need to do is keep working because then things will change for us."
West Ham manager Slaven Bilic sympathised with his opposite number for his latest disciplinary problems.
"I don't know if he deserved to be sent off, I don't know the rules," said Bilic. "I don't want any manager, especially him, to be sent off. It is hard to judge from our angle if it is a dive or a foul so I can understand it but I don?' want him to be sent off.
"I have seen him. We didn't talk about the mood but he is a gentleman. I like him."
But the West Ham manager saw promising signs of recovery in his team?s display at Old Trafford.
"It is a difficult season and I am not trying to avoid saying that," said Bilic, whose side is just a point above the drop zone.
"I am not happy with the position, we are still paying the price for September, when we had injuries -- lost against Watford, West Brom, Southampton, Middlesbrough.
"But recently there are really good performances from us. It is only a matter of time when we get the points. We could have lost today but still I would say the same thing."