Barcelona are taking inspiration from Pep Guardiola's tactics against Liverpool in the Premier League this season as they prepare for Wednesday's Champions League clash, sources have told ESPN FC.

Manchester City have earned four points against Jurgen Klopp's side in the league this season to leave themselves in pole position to win the Premier League with two games left. They won 2-1 at the Etihad Stadium and drew 0-0 at Anfield -- blowing the chance to take all three points when Riyad Mahrez missed a late penalty.

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Sources have told ESPN FC that Ernesto Valverde and his staff are confident going into the semifinal first leg this week, but they are aware the tie against Liverpool is Barca's toughest test in recent years.

Valverde has spent hours going over 24 carefully selected Liverpool games from this campaign, but it is their two matches against Guardiola's City side which he has been paying particular attention to.

The Barca coach believes the key to nullifying Liverpool's threat will be to overcome their pressing. At times City resorted to long balls and, even though Barca have never played that way, the source said it is being considered as "the last option."

"Liverpool apply very high pressure in the form of six or even seven players," a club source told ESPN FC. "They want to make you uncomfortable and, if possible, they want to rob the ball back.

"Our intention is to play as we always do. We want to get the ball at the back and play through their press. But we haven't ruled out going long if we have to."

A lot of work has also gone into analysing Liverpool's front three of Sadio Mane, Mohamed Salah and Roberto Firmino, too, while full-backs Andrew Robertson and Trent Alexander-Arnold are also players Barca know they have to pin back as much as possible.

Valverde confirmed before Saturday's win over Levante -- which saw Barca crowned Spanish champions for a fourth time in five years -- that he has been exhaustively analysing Liverpool, while centre-back Clement Lenglet also spoke about the video work players have been doing.

"To prepare [for Liverpool] I have videos of the players I am going to face," he told El Periodico. "I look at what they like to do, how they dribble, how they move, how they behave at certain moments, what foot they prefer.

"When does Robertson, for example, like to cross and where does he usually put the ball? Does Firmino prefer to go to the front post or attack the back post? I like to have every piece of information possible."

Barca returned to training on Monday to step up preparations for Wednesday's game. The players had Sunday off after winning the league on Saturday, which was followed by the trophy presentation on the Camp Nou pitch and a small party.

"I won't lie, I've had a beer and I want another," midfielder Ivan Rakitic said on Saturday. "We have the day off [on Sunday] and when we get up in the morning we may have a headache. But, after that, we have to think about the Champions League."

Valverde has no new injury concerns going into the game. Lionel Messi has started the last two matches on the bench but will return to the side for the visit of Liverpool, while Rafinha is the only Barca player nursing an injury.