Liverpool manager Jurgen Klopp has identified the manner in which his team dealt with long balls as a potential area of weakness, despite the Reds beating Plymouth Argyle in the FA Cup third round replay at Home Park.

The Merseysiders were undone by a direct approach against Manchester United in the Premier League, and were once again bombarded as The Pilgrims searched for a late equaliser.

Lucas Leiva's first goal since 2010 was enough for the Anfield club to book a fourth round meeting with Wolverhampton Wanderers as they held off the League Two promotion contenders. The Brazilian headed home Philippe Coutinho's corner after 18 minutes to secure the win, which would have been greater had Divock Origi converted a late penalty – but goalkeeper Luke McCormack made the save to keep Argyle alive in the tie.

Plymouth adopted a long-ball approach in the final minutes and almost grabbed a leveller when Jake Jervis struck the outside of the post on the volley. The tactic was similar to the one implemented by United in the closing minutes at Old Trafford on Sunday (15 January) which led to Zlatan Ibrahimovic's equaliser – but on this occasion Liverpool were not to be denied victory.

"That's normal [to be under pressure]," the Liverpool boss told BT Sport. "We should have scored in the first half with a clear penalty and that would have been the normal thing but the longer you don't score the more exciting it gets and you saw when they started getting pretty direct.

Jurgen Klopp
Klopp lent a word of advice to his team after they reached the FA Cup fourth round Getty Images

"Again we're not used to not and the defence is not often together in the last line. These situations I'm not too happy how we defended them. They had a few chances but we did especially well I would say the last 20 minutes. We controlled the game, had one or two chances but then we controlled the game again.

"We could have scored a second one. Their biggest chance was offside. Maybe it wasn't the most exciting game but for us it is very important because it was another game for a few us. Harry Wilson was involved for the first time so it is all important."

Having fielded the youngest team in their history in the first game, Liverpool started with Coutinho for the first time since his return from injury, while Daniel Sturridge was also included in a rare outing for the England international. Yet, Plymouth were competitive for long periods but Klopp was happy to accept being an equal to Derek Adams' side.

"I love this in football, that everybody can cause everyone problems," he added. "Of course we could have done this or that situation a little bit better but when you see these situations in the first half you score an early goal the game changed a little bit. These boys need confidence.

"I said at half time it might be a little embarrassing when you lose a challenge because we are Liverpool and they are Plymouth, but that makes no sense. You cannot play the game without making mistakes and losing challenges. We want to go through the next round without extra time or things like this. The next game is waiting and Wolves can come."