Former Premier League referee Mark Clattenburg once referred to Liverpool boss Jurgen Klopp as a "strange bloke" and alleged that Klopp attempted to intimidate him before a game.
Klopp is generally considered one of the more amiable and approachable managers in the English top flight. However, Clattenburg seems to have observed a different aspect of the Reds' manager.
Presently, a few fourth officials might share Clattenburg's viewpoint. Klopp joined Liverpool in 2014, resulting in three years of overlap with Clattenburg in the Premier League before the referee moved on to Saudi Arabia.
In an excerpt from Clattenburg's book, "Whistle Blower," the official recounted his initial encounter with the former Borussia Dortmund manager during a Champions League quarter-final first leg between Dortmund and La Liga giants Real Madrid.
Dortmund suffered a 3-0 defeat at the Santiago Bernabeu, leaving Klopp in a less-than-pleasant mood by the time the final whistle blew. His frustration escalated upon noticing Clattenburg taking post-match photographs of some Real Madrid players, as acknowledged by the referee himself.
"After the game, I came out of my dressing room and Real defender Marcelo and his wife asked for a picture. It was a private picture on their phone so I said yeah, no problem," Clattenburg explained. "Klopp walked past just as the photo was being taken, 'Oh, so that's why we got beat, is it?' he said. He was not being humorous or friendly, he was being sarky.
"'You're lucky you only got beat 3-0,' I said. The fact we were in Madrid probably gave me a bit of bravado to answer back. It annoyed me when managers could not be gracious in defeat."
Clattenburg's concerns with Klopp persisted. Tensions continued when the German coach took control of Liverpool, and the referee for the 2016 Champions League final delved into the notable shifts in the Reds' manager's demeanour.
"Klopp never took losing well. When he was winning he was happy, he was good fun. When things were not going his way, he got prickly. My final game with Klopp was in January 2017 against Chelsea at Anfield.
"Managers rarely came into my dressing room for the exchange of team sheets an hour before kick-off. On this occasion, Klopp came in with Jordan Henderson. It was bizarre, he stood and stared at me for about 30 seconds.
"I just stared back at him. I could see Jordan was a bit like, ‘What the hell's going on?’ Did Klopp think I was stupid? I was not going to be bullied by him. He left and all I thought was: 'What a strange bloke.'"