Liverpool players will have had nightmares about Lionel Messi after last week's Champions League semi-final at the Camp Nou.A brace from the Argentine fired Barcelona to a commanding 3-0 victory, with one of the goals being an incredible 35-yard free-kick.It meant Jurgen Klopp's men had a mountain to climb in the second leg as they looked to reach the final for a second consecutive year.Keeping Messi quiet was key to Liverpool somehow turning the tie around and one man who was determined to make it happen was Andy Robertson.Robertson recently described Messi as the best player in the world, but he had no intention of showing respect to the 31-year-old on the pitch.In the opening five minutes, Messi went down under a challenge from Fabinho outside Liverpool's box and as Robertson ran past him, he shoved his opponent's head downwards.Messi was furious as he ran up to Robertson and confronted him, at which point the referee blew his whistle and gave them both a talking to.

It was a risky move from Robertson to shove Messi's head and you can understand why the Barcelona captain was angry.

Robertson was just trying to rattle Messi, which a lot of players have tried down the years but not many have succeeded.