Liverpool's Roberto Firmino ruled out for three games with muscle injury

The Brazil international - who will leave the club when his contract expires this summer - has consistently struggled to stay fit during his final two years at Anfield.

Firmino has amassed a respectable 11 goals and five assists from 33 outings this season, but he has missed a further 10 games due to a calf problem sustained over the winter.

With only 12 Premier League starts to his name this season amid competition from Cody Gakpo, Darwin Nunez and Diogo Jota, Firmino was expected to be named on the bench for Saturday's visit of Nottingham Forest to Anfield.

However, speaking in Friday's pre-game press conference, Klopp revealed that the 31-year-old had sustained a fresh muscular problem and would not be ready to tackle the Tricky Trees on Saturday.

Following Saturday's game, Liverpool will travel to West Ham United on April 26 before hosting Tottenham Hotspur on April 30, and Klopp believes that it is "impossible" for Firmino to return before the end of the month.

"Unfortunately Bobby picked up a muscle issue a little bit. We will see how long that takes," the German told reporters.

"It's not too serious but he is definitely out for tomorrow and next week we have two more games, I would say they are impossible as well and then we will see. We have to take it day by day."

Firmino joins Stefan Bajcetic (adductor), Calvin Ramsay (knee) and Naby Keita (thigh) on the sidelines for Saturday's game, where Mohamed Salah could surge further up the Liverpool goalscoring charts.

The Egypt international currently sits seventh in the Reds' all-time goalscoring charts with 182, just one below Robbie Fowler's total of 183 in sixth place, and he broke the record for the most left-footed goals in Premier League history with his brace at Elland Road - taking him up to 107.

While Klopp hailed Salah's "insane" achievements, the Liverpool boss also jokingly warned the attacker to think of the team and pass the ball rather than shoot if the situation calls for it.

"I worked together with him for so long and was always stood more or less next to him when he broke the next record. But last week when I heard he had the most left-footed goals in Premier League history, I have to say, that's insane," Klopp said.

"When you see the names below, Fowler, Van Persie, Giggs, stuff like this, Premier League greats, absolutely. That's massive. How it always is in life, as long as you are together you appreciate some things maybe not as much as you should. We do.

"Saying that, surpassing Robbie in another stat, I know that Mo likes these kind of things and will fill his tank definitely for the game, but I don't know the numbers about his assists but that's pretty good as well, so he doesn't forget it's important or really nice to break a record but much more important that we win the game and for that you sometimes rather pass the ball than shoot yourself."

Liverpool could rise as high as sixth with all three points against 18th-placed Forest this weekend, with Brighton & Hove Albion in FA Cup semi-final action while Aston Villa travel to meet Brentford.