The Red Devils have experienced their share of questionable decisions for and against them so far this term.
After Liverpool threatened legal action against the PGMOL due to a wrongly disallowed goal in a loss to Tottenham, Ten Hag was asked if referees were good enough.
"I don't give comments often on refereeing because they do what they need to do. The standards need to be high," the Dutchman said in a press conference.
"You can expect, the fans can, a high standard, so it should be because it's the Premier League. I'm sure they do what they can. I trust them."
"We scored an own goal, that is really tough to take but I am really proud. The first red card, Curtis steps on the ball and goes over. Not a bad tackle. It looks different in slow motion. He steps full throttle on the ball and goes over the ball. That is unlucky. [For Diogo Jota] first yellow was not a yellow. Then he gets a second and to defend with nine players is tricky."
On Luis Diaz's disallowed goal, the German added: "The offside goal. That is not offside when you see it, they drew their lines wrong. The ball is between Mo's legs, they drew the line wrong and didn't judge the moment when Mo passed the ball right. It is so tough to deal with it."