Jose Mourinho felt his Manchester United were hardly done by for the second game in a row on Sunday.
United were beaten 3-1 by Watford at Vicarage Road after an apparent foul on Anthony Martial in the lead-up to the Hornets' opening goal was not picked up.
Miguel Britos and Daryl Janmaat converged on the Frenchman on the right flank before the latter skipped away with the ball and teed up Etienne Capoue for the home side's 34th-minute opener.
Mourinho was quizzed on the incident in his post-match press conference and felt that even being asked about it shows there was something wrong with the tackle.
"When you come with that question it's because you know," said Mourinho, who also questioned a missed offside cal in the 1-0 loss to Feyenoord on Thursday night.
"You don't ask me about that if you think that nothing happened. The reason you asked the question is my answer.
"The referee's crucial mistakes are not in my control, there is nothing I can do about that.
"That is not under my control."
Mourinho also picked out another incident which occurred against Manchester City when Claudio Bravo appeared to foul Wayne Rooney.
He added: "But against Man City you know what happened in minute 55, today you know that happened for the first goal, against Feyenoord there was the offside goal.
"So we were punished by these mistakes and I can't do anything about it."