Manchester United take on their age-old rivals Liverpool on Sunday at Old Trafford. The two sides know that once the whistle blows, their form goes out of the window.Ole Gunnar Soskjaer is under pressure at Old Trafford right now but the board still seem to be backing their manager. However, he is losing the support of the Red Devils worldwide and the Norwegian knows he needs a win at all costs.Things are not going to be easy for Manchester United as the odds are stacked in Liverpool's favor.Here are 5 reasons why Manchester United will struggle against Liverpool#5 Injury issues for Manchester UnitedManchester United@ManUtd🚨 The boss has news on @RaphaelVarane's injury...#MUFC | #MUNLIV3:05 PM · Oct 23, 20216318362🚨 The boss has news on @RaphaelVarane's injury...#MUFC | #MUNLIVRaphael Varane and Antony Martial are out of the Liverpool clash tomorrow. Manchester United might have more issues as Ole Gunnar Solskjaer has confirmed Bruno Fernandes, Fred and Marcus Rashford are also doubtful.While speaking to the media ahead of the big game on Sunday, Ole said:"We've had some knocks, which you expect during games. That's good, that we get some players giving everything, and then we just have to assess them. I'm not going to rule anyone out from Sunday but I'm not sure if everyone's going to be fit. Anthony is still working on his fitness, hopefully, he's come through today and let's see how he is tomorrow.""Games like Wednesday will always bring knocks and bruises. We have two or three with knocks but I hope I can pick from a fit squad. Bruno might be a doubt but he's doing everything he can to be fit. I can't say if Fred will be fit or not. We might have the whole squad fit but may miss two or three. We'll see."Bruno will undoubtedly be the biggest miss for the Red Devils are they need him to create chances. Manchester United fans will be praying that the Portuguese star is fit to play at least in the second half.#4 Attackers not clickingManchester United@ManUtd2️⃣4️⃣ hours to go 🔥#MUFC | #MUNLIV9:00 PM · Oct 23, 20212395817252️⃣4️⃣ hours to go 🔥#MUFC | #MUNLIV https://t.co/U4ocx7jrAKAfter pursuing him for over the entire summer of 2020, Manchester United acquired Jadon Sancho in 2021. The Englishman was seen as the missing piece in the Red Devils attack but, he has so far, turned out to be the clog.The addition of Cristiano Ronaldo sure made the Manchester United attack look ruthless on paper. But on the pitch, they worked better with Edinson Cavani up front. Ole needs to work on a tactic to get the attack ticking with the Portuguese superstar as they need the three up front to be at their best tomorrow.