Jurgen Klopp told Liverpool to get ready for a battle as they look to get their Uefa Champions League campaign back on track after defeat to Napoli. Last season’s finalists, who began the current campaign with a stirring 3-2 win over Paris Saint-Germain, host Red Star Belgrade on Wednesday night, with Klopp quick to guard against complacency, even though the Serbian champions lost 6-1 to their French counterparts. "Serbian teams are always well organised and they know how to defend,” he said. “We need to be ready for a really hard fight. We need to fight for every square metre of space.” Red Star also held Napoli in a stalemate and Klopp added: “Red Star are the team of Serbia, and made it really difficult for Napoli. And for PSG, even if the score wouldn't make you think so. It was impressive how they defended against Napoli. They are living the dream. <strong>_____________</strong> <strong>Read more:</strong> <strong>Ian Hawkey: <a href="https://www.thenational.ae/sport/football/barcelona-v-inter-milan-conjures-up-memories-of-volcanic-semi-final-in-2010-1.783419">Barcelona v Inter Milan conjures up memories of volcanic semi-final in 2010</a></strong> <strong>UCL talking points: <a href="https://www.thenational.ae/sport/football/uefa-champions-league-talking-points-real-madrid-look-for-solace-and-pressure-on-thierry-henry-1.782814">Real Madrid look for solace and pressure is on Thierry Henry</a></strong> <strong>Richard Jolly: <a href="https://www.thenational.ae/sport/football/mohamed-salah-on-target-as-liverpool-beat-huddersfield-to-keep-pace-with-manchester-city-1.782595">Mohamed Salah on target as Liverpool keep pace with Manchester City</a></strong> <strong>_____________</strong> “For Red Star, the challenge a little bit is that they are that dominant in Serbia. They win 80 or 90 per cent of games, but Champions League is different. And in Paris, had they had opened Pandora's Box, then ...." Liverpool, who had only scored three goals in their last five games, have not been that potent of late but are boosted by the news Sadio Mane is available again. The winger missed Saturday’s 1-0 win over Huddersfield Town after undergoing surgery on a broken thumb he sustained playing for Senegal. “Sadio has trained the past two days completely normal,” Klopp said. “He is in contention.” But Liverpool will be without midfielders Jordan Henderson and Naby Keita, although the summer signing is training again. The captain has “a little hamstring injury” that will also keep him out for Saturday’s clash with Cardiff. It could mean just a second start for Fabinho, the summer signing who was a Champions League semi-finalist in his Monaco days, or Klopp could choose to use Adam Lallana or Xherdan Shaqiri as a more attacking option. At least James Milner and Gini Wijnaldum have been passed fit. “Milly looks fine. Gini got a knock on his Achilles but should be okay,” added Klopp. Red Star have an injury problem of their own, with the former Chelsea winger Marko Marin ruled out. While Liverpool have been less potent from last season, they have only dropped four points and conceded just three goals in the Premier League and Klopp took solace from their resilience, consistency and defensive excellence. "The first job we have is to win football games,” he said. “We compare always with the good games of last season, never the average ones. All the games we won [this season] we probably deserved to win. And when we lost to Napoli, we deserved to lose. “Of course, we can do a lot of things better than we did so far. But the basis we have created is pretty good, football-wise and point-wise. Now we have to build on it. “So far, so good. Let's see if we can stay in the race. That would be really cool. Imagine you have a normal start to the season, with 18 points. Then you are five behind and it is difficult. It looks like it will be a very interesting season, and that's good news." Liverpool have made their best ever defensive start to a league campaign and Klopp added: “It's the basis for all successful teams; it shouldn't be easy to score a goal against us. We don't concede a lot of shots on target, and that's defending. Our defensive solidity is hard work, you have to really fight for it." This is a meeting of former European champions, with Red Star before an exodus of their players led to a shift in the pecking order, but Klopp’s memories of the team of 1991 are hazy. "I was 23 at the time and obviously I had better things to do than watch,” he smiled. “But it was an outstanding team."