When Sheffield United's Chris Wilder met Liverpool's Jurgen Klopp

It is a little sketchy on detail. Others, who were present in the room when they met properly for the first time, have instead been left to fill in the gaps.

But whenever he casts his mind back to September’s Premier League fixture against Liverpool at Bramall Lane, it becomes abundantly clear that Sheffield United manager enjoys the German’s company. They might move in different circles. They are acquaintances rather than friends. But by agreeing to talk football over a post-match beer in his office, Klopp earned Wilder’s respect. Others, even at that early stage of the season, had already chosen to ignore what the 52-year-old regards as a sacrosanct tradition.

“He came in for a chat,” Wilder recounted again recently. “And I thought that was a great touch from him. It’s something I think is important. We should be building relationships. It’s always a shame when people don’t seem to feel the same.”

Tomorrow night, when United travel to the North-West for the return match on Merseyside, Wilder will be looking forward to enjoying Klopp’s hospitality. Ideally after watching his team become the first to beat leaders Liverpool in the top-flight this season. But, win lose or draw, two of the most talked about coaches in the business are likely to spend half an hour or so chewing the fat following the final whistle. Given events at their respective clubs since that previous get-together, they will have plenty to discuss.

While Klopp’s men appear destined to end their 30 year wait for a title - after being crowned world club champions in the Middle East last month - United have been making, in relative terms at least, equally impressive progress. Described as certainties for relegation at the beginning of the campaign, they finished last weekend in eighth after taking points off the likes of Arsenal, Tottenham Hotspur and West Ham.

Despite drawing with Chelsea only four months after being promoted, their tussle with Liverpool proved to be a pivotal moment in United’s campaign. Despite losing 1-0 in heartbreaking circumstances, when a goalkeeping error gifted Klopp’s men the win, posing such illustrious opposition so many questions persuaded Wilder’s squad they belonged at the highest level.

“Sometimes I think we believe in them more than they do,” he had commented a few weeks earlier following that trip to Stamford Bridge.

Crucially, given the physical demands of elite level competition, getting close up and personal with the reigning European champions also convinced United they were tough enough. Because, as Wilder later acknowledged, the days when sides fresh out of the EFL could hope to knock the best out of their stride are long gone thanks to the advancement of fitness techniques and sports science.

“I remember being stood in the tunnel when he (Klopp) walked in, thinking ‘He’s a big bloke.’ Much bigger than he looks on television,” Wilder laughed. “Then Jordan Henderson came through and it was the same thing. Even though you wouldn’t particularly regard him as being a really big player, you saw he was actually this six foot something tall athlete who can obviously play too.”

“Obviously, it goes without saying, that the technical side of things have been driven up,” Wilder continued. “Everyone knows that. But the bit a lot of people don’t realise is that it’s even more physical too. Our lads have worked hard and I think our record, in terms of results and injuries, shows they’ve upped their levels as well.”

Although Liverpool have suggested they could rotate the options at Klopp’s disposal, United are expected to wait until Sunday’s FA Cup tie against AFC Fylde before resting those players who have been virtual ever-presents so far. Former Everton midfielder and lifelong Liverpool fan John Lundstram is a doubt, together with goalkeeper Simon Moore. But Wilder is aware, if United are to cause an upset, they must select a full-strength eleven. Or as near as possible.

“We respect everyone,” he said. “No matter who we’re up against, we always respect them and obviously you can’t have anything else for what some of the people we’re facing hace achieved. But we don’t fear anyone. We don’t want to go anywhere and be passive. We always want to win and we want to give ourselves the best possible chance of doing that by showing the right attitude.”

With Liverpool also exponents of attacking football, an absorbing game appears to be in prospect.

“One of the things which has really pleased me,” Wilder said, “Is the fact our lads have always shown that attitude. I always know what to expect from them in that regard, because they always hit the levels. There’s nothing worse or more frustrating as a manager than going into a match not really knowing, mentally, what you’re going to get from your team.”

Their last face-off with Liverpool also reminded United about the importance of being clinical. John Fleck and Oli McBurnie enjoyed half chances early on before substitute Leon Clarke missed a glaring one to equalise after Georginio Wijnaldum had broken the deadlock.

The outcome also provided an insight into the outlook which, combined with some intelligent recruitment, has helped Wilder and his assistant Alan Knill drive United up the rankings.

“I’m not bothered about plaudits or anything like that,” he said. “I’m not interested in people saying ‘well done’ or ‘didn’t you do well.’ Getting rubbed on the head and all of that.

“What we are interested in is points and results. Liverpool weren’t at their best and I feel we’ve missed an opportunity.”

Clouded by emotion, Wilder’s analysis of the clash did not do United’s display justice. But he will be determined, if the opportunity presents itself, they are not left with a sense of what might have been again.