Arne Slot likened Plymouth Argyle's tactics of using long balls to Manchester United's display at Anfield after Liverpool suffered a shock 1-0 defeat in the FA Cup fourth round.

Ryan Hardie’s second-half penalty was enough to send bottom-of-the-Championship Plymouth into the fifth round at the expense of the Premier League leaders.

Slot had made 10 changes to his side from their last outing, with the likes of Mohammed Salah, Cody Gakpo, Dominik Szoboszlai and others not included in the squad.

This was only the second time in the last 11 years that Liverpool have been eliminated from the FA Cup by a side from outside the Premier League (also 2016-17 v Wolves).

The Reds had 14 chances overall, with four of those shots on target, both higher totals than their opponents. However, they struggled to create much of note apart from two late chances which Conor Hazard superbly saved.

Slot admitted Liverpool have struggled against similar tactics to what Plymouth employed in past games, noting the similarities to how Ruben Amorim set up United in their 2-2 draw in January.

"I think we've seen during this season, we've seen a few times already, that it's a game plan, a playing style, which is difficult for our starters, but also for the ones that played [on Saturday]," said Slot.

"So, constantly long ball, second ball, long balls, second balls. It's difficult for every team.

"We had it with United at home, for example, as well. They had a similar playing style, going to a very low block [then] kick every ball long, and then we played with our starters."

Liverpool suffered just a fourth defeat under Slot since he replaced Jurgen Klopp at the end of last season. In fact, they accumulated an open play xG (expected goals) of just 0.44 today against Plymouth Argyle, their lowest in a game under Slot so far.

"The result is obvious, it's a big disappointment, and the way we played [there] wasn't a lot to be happy about as well," Slot added.

"You never know what will happen if we would have played with our starters over here.

"I think [it] also showed why we played with the ones we played with because these players need game rhythm as well.

"For them to be ready in the upcoming months, they need game time, and you saw today that some of these players really need games like this to be ready for the last three months of the season."