Three years ago this week Liverpool travelled to Old Trafford with both teams treading water in the battle to haul in Chelsea at the top of the Premier League table.
A 1-1 draw helped neither side really, keeping United five points behind their Merseyside rivals, while Antonio Conte's Chelsea disappeared over the hill and towards the title.
The January 15, 2017 game did turn out to be a staging point on Liverpool's rapid rise however. Three years on they are setting records at the top of the Premier League, champions of Europe and on course to end a 30-year title drought, while powered by the creative brilliance of a home-grown full-back.
Trent Alexander-Arnold made his first Premier League start for Liverpool that day and while he's had some difficult moment during his development since then, he's now the best attacking right-back in Europe, with a Premier League high 20 assists since the start of last season.
In three years the two teams have followed different trajectories. Liverpool's steady progress under Klopp is being rewarded, while United have enjoyed the peaks and troughs of Jose Mourinho's reign and are now preaching a long-term project under Ole Gunnar Solskjaer.
They head to Anfield 27 points behind Liverpool but they also have a crop of promising, home-grown youngsters that hint at a brighter future. One of them, in Brandon Williams, could yet turn out to be their own Alexander-Arnold.
If Williams does start on Sunday it will be the biggest day so far of his fledgling United career. The 19-year-old has made five Premier League starts and did play against Manchester City in the Carabao Cup last week, but trying to stop Mohamed Salah at Anfield will be his toughest challenge.
It's what United fan Williams offers going forward that excites however. United have lacked an attacking threat from full-back recently, but Williams looks like he could change that.
He has already won a couple of penalties for United with adventurous surges into the penalty area and he scored his first Premier League goal with a thumping effort in the 3-3 draw at Sheffield United. There have also been some dangerous deliveries into the box that have gone unconverted, noticeably against Burnley when he produced fine crosses on his right foot, from deep, and from his left when darting to the dead-ball line.
This season his expected assists stand at 0.83, compared to 0.53 for Luke Shaw. While those figures are way behind Alexander-Arnold's 10.15, he wasn't producing numbers like that in his first season in the side. Williams is heading in the right direction. His expected goals figure of 1.51 is well ahead of Shaw's 0.34. Alexander-Arnold is at 2.61 but Williams' record is better when looked at per 90 minutes, while he also hits the target with more of his shots.
These are very early days for Williams in the United side, but the signs have been promising so far. Like Mason Greenwood he looks to have a future at Old Trafford and, like Alexander-Arnold, he could become the beating heart of a successful United side.
Source: m.allfootballapp.com