#3 Starting Robertson over Moreno
When Klopp took over the reins in 2015, he was unhappy with what he saw of Alberto Moreno, and it seemed like the Spaniard had no future at the club. Things went from bad to worse when James Milner was played as a left-back for the entirety of last season, restricting Moreno to a meagre two league starts.
This summer, Liverpool signed Andrew Robertson from Hull City, and it was expected that the Scotland international would walk straight into the starting eleven. However, due to Moreno's impressive pre-season, he has been Klopp's go-to man on the left side of defence, starting in five of the Reds' seven league games.
While it can be argued that Moreno has done a decent job, Robertson provides more of an offensive threat for Liverpool and was also named man of the match on his league debut for the club against Crystal Palace.
The former Hull City defender is an exceptional crosser of the ball and his positional awareness makes him a force to be reckoned with. Still to be tested against bigger opposition, the time may be right for Klopp to take a gamble and start the 23-year-old against United.
Robertson is exceptional at overlapping the wingers and is also capable of playing as an auxiliary wide man if the situation demands. He was signed because of his versatility and adaptability, and only needs one good game against a top side to cement his place in the Liverpool starting eleven.