Jose Mourinho has suggested that Jurgen Klopp is given preferential treatment by match officials following Manchester United's 0-0 draw with Hull CIty.
The Liverpool manager was forced to apologise after his outburst at a laughing Neil Swarbrick on the touchline during Liverpool's meeting with Chelsea on Tuesday.
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Reds boss Klopp was angered by the decision not to award a free-kick to Liverpool in the build-up to Joel Matip conceding a penalty that was eventually missed by Diego Costa.
The German confronted Swarbrick but revealed afterwards that he said sorry and even admitted that, to his surprise, the fourth official apparently told him "no problem, I like your passion".
And now Mourinho has picked up on the way he is personally dealt with by match officials, suggesting that the rules are different for other managers.
"The rules for me are different," Mourinho insisted after watching his side stutter to a 0-0 draw at home to Hull City that sees them miss the chance to cut the gap in the race to finish in the top four.
He added to Sky Sports: "I don't want to speak much because I pay lots of fines. I pay more than others, much more than others.
"For example, yesterday one manager was told by an official 'I love your emotion'.
"Today [Wednesday] I was told to sit down or I have to go to the stands. On the pitch was the same. I don't want to speak much because I don't want to pay fines.
"They [match officials] don't like my emotion. I think what happens this season [Mourinho's fines] is not for me to say."
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Mourinho had previously had a veiled swipe at Klopp in comments made after his side reached the final of the EFL Cup, insisting the wind at Wembley stadium meant they are not favourites against Southampton.
That was after former Dortmund boss Klopp had himself appeared to blame the blustery conditions at Anfield as part of the reason his side were dumped out of the competition by the Saints.
The result on Wednesday night means United are now four points behind fifth-placed Manchester City in the table, where all three points against Hull would have seen them just three behind Tottenham in second.