Liverpool head coach Arne Slot has described his team's shock FA Cup exit at the hands of Plymouth Argyle as "unacceptable" and has urged his players to "show a different side" in the Merseyside derby against Everton on Wednesday.

Liverpool were knocked out of the FA Cup thanks to a Ryan Hardie penalty, with Slot having rested several key players for Sunday's trip to Home Park.

The Premier League leaders also lost defender Joe Gomez to injury early on in the clash, but Slot believes his team should still have had the quality to beat the side who are rock bottom of the Championship.

"To lose against Plymouth is unacceptable," he said in a news conference on Tuesday. "We are disappointed with that result. Now we have to show a different side of us tomorrow. It was not only the result, but the performance was far below Liverpool standards as well."

Slot has been criticised in some quarters for failing to respect the FA Cup, while others have argued that being dumped out of the competition could actually help Liverpool in their pursuit of the Premier League, Champions League and Carabao Cup, having booked their place in the final of the latter competition last week.

"A wise man once said to me nothing good comes from losing a football game and I completely agree," Slot said. "We would definitely prefer to have played more games. Now after losing this game, there is one moment where we have a normal week but that is not what we wanted when we went to Plymouth.

"It was difficult because the plan was to play with Joe [Gomez] for 60 minutes, the plan was to start Curtis [Jones] but he didn't feel well enough to play so then all of a sudden, we missed two important players. Darwin became a dad one or two days before the game, that happened in Spain, so he came in one or two days earlier.

"There were some circumstances that weren't perfect. The idea was to play with a stronger team than we did but still this team should have been able to win that game. The fact we didn't win and that we didn't win against PSV [Eindhoven] as well tells us that these players need these games to get the best out of them. It's so difficult to get the best out of them if you don't play games. It makes it disappointing we don't have these extra games for them."

Starting with the game against Everton, Liverpool face a gruelling run of five Premier League matches in 15 days.

Asked whether this upcoming stretch will define his team's season, Slot said: "No, because this, playing five games in 15 days, is what we've done for seven months now. Every phase of the season is crucial if you play in the Premier League.

"This is the hardest league to win because there are so many teams that can win this league and there are so many teams that are able to win 10 or 15 games in a row. You cannot slow down, you cannot have a few games where you are not on top of your game because all of a sudden other teams catch you up.

"That's why it's such an exciting league. The upcoming five are important but then after that the next nine are important. But the first 23 have been just as important."