​Liverpool manager Jürgen Klopp has admitted he will have to spend a long time preparing plans to stop Barcelona star Lionel Messi when the two sides meet in the Champions League semi-finals.

The Reds qualified for the last four after easing past Porto 6-1 on aggregate on Wednesday night. There they will face the Catalans, who dismissed Manchester United 4-0 during their own quarter-final tie. Messi grabbed a quickfire brace in the return fixture at the Camp Nou to continue his exquisite form of late, those goals taking him to eight in his last five appearances in all competitions.

Lionel Messi

The magical Argentine's tally for the season stands at a sensational 45 goals, matching his total for all of the last campaign despite having played 12 less games. His scintillating form has led many to make ​Barça favourites to win this year's ​Champions League, given ​Messi's ability to single-handedly dismantle opponents.

Klopp appears to hold the forward in equally high regard. He was asked after ​Liverpool's victory in Portugal about how he planned on shackling the five-time Ballon d'Or winner and stated (as quoted by the ​Mirror): "Thank God I don’t have to think about that tonight. 

"I have a few nights. No one has so far managed it, but we will try. We have a few jobs before that," the 51-year-old finished, evidently concerned about Messi's supreme talents.

The German has ample reason to be worried, with the Barcelona man's double against ​United taking him to a total of 24 goals against English sides in European competitions.

That is double the amount that rival ​Cristiano Ronaldo has netted when playing ​Premier League clubs in the Champions League.

Klopp may take heart from the fact that Messi has never notched against the Reds, though he has only featured twice against them. Those matches both came back in 2007, when the Argentine was still a raw, untamed teenager.