#2 Andrew Robertson
Andrew Robertson has been a crucial part of what has made Liverpool so strong at the back. He covers so much ground on the left flank that he's almost playing as a left winger, too. Once he's driven the ball towards the by-line, he will whip in a ball to a teammate, who, more often than not, will score.
Robertson has nine assists for the Reds and has played in 31 out of 33 games this season. His importance in the squad isn't just acknowledged at Anfield, but also for the Scotland national team, which he now captains.
The left-back has been one of the best buys for the Reds in recent seasons, as they only paid £8m for him when they signed him from Hull City in the summer of 2017. He now has a market value of £50m, which is a testament to how well Liverpool have managed and developed him since then.
With him only being 25 years old, Robertson has a lot of time to perfect his craft, so don't be surprised if he turns out to be the best left-back in the world in the next few years.