Jurgen Klopp remains hopeful Jordan Henderson will be back in action for Liverpool before the end of the season after undergoing groin surgery.

The Liverpool captain was injured during the first half of the Merseyside derby defeat to Everton last Saturday. It is unclear when exactly he will return, though the club has confirmed Henderson will not feature prior to the international break in March.

Klopp was not willing to be more specific over a comeback date for the midfielder when he spoke at a news conference ahead of Sunday's trip to Sheffield United.

However, the Reds boss was clear that, despite not being able to participate on a daily basis, Henderson - like Liverpool's other long-term absentees - can still have an influence on the rest of the squad.

"They all have to be influential [while out], that is clear with so many players unavailable at the moment. Most of them are leaders in this group, here doing their rehab," Klopp said.

"Hendo is not here yet but Virgil [van Dijk], Millie [James Milner] and Joel [Matip] all have to be influential here. That's what they will be. When Hendo is back, he will have to play this role while doing his rehab.

"The best-case scenario? I don't know, to be honest. It's not a quick one, but of course we all hope there is still a possibility for him to play a few games this season, but we will see."

Henderson will miss Premier League games with Chelsea, Fulham and Wolves next month, as well as the second leg of the last-16 Champions League tie against RB Leipzig. There are also three World Cup qualifiers for England that he must sit out.

The 30-year-old has started 20 times in the league this term, during which Liverpool have a 45 per cent win percentage and an average of 1.7 points per game.

Unsurprisingly, those figures drop when the skipper is missing. Klopp's side have won two of their five outings in the league when Henderson - so often used as a makeshift centre-back due to injuries in defence - has not played, averaging 1.4 points per match. They have also faced more shots, the average rising from 7.8 per game to 10.

There is some good news for Liverpool over the return of Diogo Jota, while Fabinho is also set to resume training ahead of Sunday's trip to Sheffield United.

Jota has not played in 2021 due to a knee injury but Klopp will not take any unnecessary risks with the forward, even with his side struggling to score goals.

"Diogo trained twice with the team and has looked very good, very good," Klopp said. "But he was long-term out and we have to see what we can do with that, though in training he looks really promising."

Asked later if Jota's return is a timely boost in the battle to secure a top-four finish in the Premier League, Klopp replied: "Of course it's positive, but it's not the only positive.

"It's very positive that Diogo's back after a long time, the others who are out for a long time we will not see any more on the training pitch until the end of the season.

"Yes, it's very positive, and the way he came back in training is very positive. We just have to make a decision about what makes sense for him, when it makes sense for him, these kind of things."

Liverpool travel to bottom club Sheffield United on Sunday on the back of four straight defeats in their title defence; they have not lost five in a row in the top flight since a slump spanning August and September in 1953.

Klopp confirmed no decision had been made on the availability of Alisson for this weekend following the death of the goalkeeper's father back in Brazil.