No phone calls, no texts and no contact is the order of the day, and the pair stuck to that routine ahead of last weekend’s meeting between Huddersfield Town and Liverpool.
This extended to ignoring each other effectively on the touchline last Saturday tea-time as Mo Salah’s 50th goal in English football proved enough to deny Wagner a belated 47th birthday present at the expense of the Reds chief.
Once the final whistle had blown, however, friendship was resumed quickly with Klopp’s depth of feeling for his compatriot clear for all to see during a joint post-match interview on BT Sport as he ran through the tough schedule that Huddersfield have faced in their opening nine games.
“It is the hardest fixture list I have heard about,” added Klopp.
Such support is understandable. Wagner was Klopp’s best man after all.
But the Anfield chief is clearly genuine in his admiration for not just the job done by Wagner at Huddersfield over the past three years, but how Town operate as a club, too.
“There is no reason to be worried about Dave’s situation at Huddersfield,” said Klopp when asked earlier about his friend’s job security in the West Riding.
“Getting promoted there – I use the words of a friend – is a miracle.
“Staying in the league is a miracle, and now this year if he stays in the league then he has a hat-trick of miracles.
“If people are now waiting for the third time and think, ‘What are they doing?’ then you can’t talk to these people about football.
“Fortunately these people don’t work at Huddersfield. They found a situation where they work together, they trust Dave, rightly, 100 per cent.
“We can say Liverpool could be managed by a lot of managers because they have a fantastic team and they are an outstanding club.
“But I don’t think any other manager in the world could do the job Dave has done at Huddersfield. Nobody needed Huddersfield in the Premier League, but now they are there because they did what they did.
“I don’t think they will lose confidence early.
“Each player knew before the season that it would be hard.
“They were ready for it, hard work, now they fight.
“I am not worried about Dave’s situation at Huddersfield because there is no need to be.”