Liverpool's youngster ever starting XI were left frustrated by the League Two side and they will now have to travel to Home Park for the return fixture.

The much-changed Reds dominated the tie at Anfield but, ultimately, struggled to break through a determined Argyle defence.

Speaking at a news conference after the game, the Reds boss joked that he was thankful Liverpool supporters did not leave the stadium early due to the lack of action on offer.

"I have a lot of good things [to take away from the game]," Klopp said. "I know nobody wants to hear this because we are Liverpool, but football is like this and we tried.

"Better decision-making in a few different situations and we are completely through. That's how football is.

"The biggest challenge in football is to play against a deep-defending side. Maybe Plymouth, in this moment, is happy about the result. They deserved the rematch."

Klopp added: "I don't think they [Plymouth] could attack actually. We had the ball all the time and [they had] a few counter attacks.

"We always waited until Plymouth was back [organised] again and then we started passing the ball.

"It was boring. I'm happy that the Liverpool crowd didn't leave the stadium after 60 minutes or something because it was not the most exciting game."

Liverpool had 77 percent of the possession in the contest, but only forced four shots on visiting shot-stopper Luke McCormick's goal.

Argyle boss Derek Adams hailed the performance of his side as one of the best Anfield has ever witnessed.

"I think it's one of the best defensive performances that Anfield has probably seen," Adams said of his team's organised display at a news conference.

"We defended deep, we defended in numbers and we've allowed Liverpool to have the ball. That was the gameplan. You've got to stop good players having space and time. That's what we did today.

"We wanted to win the match. We thought we would have a couple opportunities in the game and we did. We didn't take them.

"We limited Liverpool to not many [chances]. They got into the wider areas and put crosses into the box and we dealt with them well.

"I think the players have worked extremely hard today. It would be naive as a coach to come to Anfield and think you can go at top-class players."