FIFA ref Jonas Erikkson has taken a swipe at Arsenal defender Stephan Lichtsteiner.
Erikkson, who refereed the 2013 UEFA Super Cup final, blasted the defender as a nightmare to deal with.
"I have met several international players and to judge a person, you have to meet them several times – and not just once when they have a bad day," he explained to SVT.
"Because everyone can have it. But I have met Lichtsteiner several times and he is one of the most unpleasant players I met.
"You cannot talk to him, he gets more and more angry.
"When I'm trying to explain [my decision], I'm trying to be humble, but he's hard to get in touch with. It creates a bad mood."