Manchester United are a better footballing side under Ruben Amorim, that is undeniable. They move the ball far quicker and with a purpose that was largely lacking under the Portuguese manager's bumbling predecessor Erik ten Hag, whose poor decision-making set the club back years. Fans are getting proper entertainment in exchange for their money and time again, which means Amorim has hit the minimum requirement 13 months into his reign.In October, United part-owner Sir Jim Ratcliffe moved to quash talk of Amorim's position being under threat, saying he wants to give the ex-Sporting CP boss three years to prove himself as a "great coach" at Old Trafford. That was the right call given the signs of progress, but as ever at a club the size of United, results are the only thing that really dictate the manager's future, and with the midway point of the campaign almost upon us, they are still not good enough.The Red Devils produced another improved performance at Aston Villa on Sunday, but still slipped to their fifth Premier League loss of the season, ultimately undone by the brilliance of Morgan Rogers. As a consequence, Amorim's side are 13 points adrift of leaders Arsenal after just 17 games and three behind Liverpool in fifth, which is likely to be the last Champions League spot once again due to the English top-flight's strength in UEFA's coefficients rankings.With only two wins in their last eight, United are not showing the consistency required to secure a return to Europe's top table. That's partly a mentality issue, but the main reason is the short supply of real quality running through the squad, an issue laid bare with Bryan Mbeumo, Amad Diallo and Noussair Mazraoui all now away on Africa Cup of Nations duty.Amorim doesn't have the luxury of strength in depth, so it was always going to be an uphill battle to maintain a Champions League push. But he needs a miracle after seeing evergreen club captain Bruno Fernandes come off injured at Villa. Make no mistake, losing Fernandes, the one constant for United in terms of level and availability, is a catastrophic blow that could completely derail the season and leave Ratcliffe under huge pressure to pull the plug on the Amorim project two years early.In typical fashion, Fernandes was the maestro behind most of United's best moments in the first half against Villa, as he set up one big chance and completed 89 per cent of his passes. But shortly before the interval, the 31-year-old pulled up feeling his hamstring, and the visiting fans held their collective breath.Fernandes played on until the whistle, but couldn't return to the pitch for the second half, with Lisandro Martinez introduced as his replacement. Instead, the Portugal international was seen limping to the dugout, clearly in discomfort, with Diogo Dalot later saying to Sky Sports: "It’s massive, we don’t know how bad it is but for him to come off the game…"That statement of shock and concern reflects how reliable Fernandes has been since his switch to United from Sporting in January 2020. He's only missed three matches due to injury in his six years at the club, one because of a bout of flu in March 2022, and two due to a knee complaint towards the end of the 2023-24 season.This could very well be the most serious fitness setback of Fernandes' United career to date, as Amorim hinted at when he spoke to reporters after the game: "It is really strange. It’s a soft tissue, I think he’s going to lose some games, I don’t know for sure. Let’s see. I think it’s going to be a while. He is a guy who is always fit so he might recover quite well."Fernandes' importance to United cannot be overstated. He's already racked up a team-leading 12 goal contributions in the league this term, five more than second-placed Mbeumo, despite being asked to drop into a defensive midfield role in Amorim's 3-4-3 set-up.The defeat to Villa marked only the fifth Premier League game in which United have scored that Fernandes has failed to be involved in at least one goal. He's their chief creator and goal threat, a fierce competitor who takes games by the scruff of the neck, demands the highest standards from all those around him, and runs himself into the ground for the cause.Amorim has confirmed that Fernandes will definitely miss United's Boxing Day clash with Newcastle, and it has been reported he could be out for at least a month. They simply cannot cope that long without him. Key centre-half duo Matthijs de Ligt and Harry Maguire are already in the treatment room, along with Kobbie Mainoo, and unless the Ivory Coast, Cameroon, or Morocco suffer a humiliating group-stage exit at AFCON, Mbeumo, Amad and Mazraoui won't return until the Red Devils travel to Burnley on January 7 at the earliest.The growing list of absentees worked in favour of academy graduates Shea Lacey and Jack Fletcher, both of whom were handed their Premier League debuts against Villa, but Amorim is being forced to stretch the squad to the limit, and Fernandes is by far the biggest loss yet. There is no one in the squad capable of filling his boots at this vital stage of the season.On the plus side, United will welcome Casemiro back for the visit of Newcastle, with the Brazilian having sat out the Villa game as punishment for accumulating five yellow cards. The Real Madrid legend has been fiercely criticised throughout his time at Old Trafford, but has been more disciplined in his work off the ball this season, often winning it back high up the pitch to lead quick transitions.Casemiro possesses an excellent passing range and always poses a danger from set-pieces with his aerial prowess, while he's also an expert reader of the game who does much of the dirty work in winning duels and making interceptions. However, at the age of 33, Casemiro is not as mobile as Fernandes and cannot get up and down the pitch as quickly; it's too much to ask for him to suddenly take on all of the same responsibilities.So the question becomes, who is the ideal partner for Casemiro while Fernandes is out? Martinez produced a competent showing after stepping into midfield in the second half at Villa Park, but he is a defender by trade and doesn't have the powers of invention to make a permanent transition, while Fletcher - son of former United favourite Darren - is too inexperienced at 18.Mainoo, meanwhile, missed the Villa game with a calf issue that Amorim has said could take "a few weeks" to heal. The England international is a technically-gifted midfielder who could perhaps drive United forward more efficiently than a prolific risk-taker like Fernandes, but even if he was fit, there would be no guarantee of minutes, because for whatever reason, Amorim doesn't see Mainoo as the right fit for his system.Add GOAL.com as a preferred source on Google to see more of our reportingThat leaves Manuel Ugarte as the last option for United, which sums up how bleak the situation is. With Casemiro and Mainoo out, Amorim was forced to start Ugarte at Villa, but the Uruguayan blew his big chance to prove himself.Ugarte lost half of his ground duels, gave away possession seven times and didn't attempt a single clearance in the match. He also completed just 27 passes in his 77 minutes on the pitch, and went viral for an awfully misjudged one that floated out for a goal-kick. United have not won any of the last nine matches that Ugarte has started, a club record only 'bettered' by much-maligned World Cup-winner Kleberson between January 2004 and May 2005, and that is no coincidence. The former Sporting and Paris Saint-Germain ace works hard, but his style of play is ugly and ineffective, and he has no positional sense to speak of.The step up to the Premier League has been too great for Ugarte, which even Amorim has acknowledged after previously working with him in Portugal. "I know that Ugarte is struggling in the moment, and my job is trying to help him to feel as a player, like I felt when he was a Sporting player," Amorim said last month. "But it is a different world, and he needs to adapt, and he needs to improve, especially in training."There has been no visible improvement since those comments, and United's struggles will worsen if he continues to get the nod. In the short-term, Amorim should stick with Martinez, who is a composed, progressive passer who channels his aggression far more wisely than Ugarte. United desperately need reinforcements in the middle of the park if they are to remain in the top-five race while Fernandes is on the sidelines. Midfield has long been a clear weakness in the squad, and a host of specialist players have been linked with moves to Old Trafford in recent months, from Nottingham Forest's Elliot Anderson to Brighton's Carlo Baleba, the latter of whom was reportedly the subject of firm inquiries from United over the summer.The Red Devils are also said to be on red alert after the revelation that Ruben Neves is plotting a return to the Premier League after turning down a new contract at Al-Hilal. The former Wolves talisman, and long-serving team-mate of Fernandes with Portugal, is exactly the kind of tempo-dictating playmaker United have been crying out for, and is still in his prime at 28.The Times have suggested that Neves could be available in the winter window for a bargain fee in the region £20 million ($27m), which feels like an opportunity that is too good to miss, but Amorim is taking a hard-line stance when it comes to mid-season transfers."What we cannot do is to reach January and try to do everything in urgency, make mistakes and then [it's] 'here we go again' with a lot of mistakes," the no-nonsense coach said on Sunday. "I'm not going to get [together] with [technical director] Jason [Wilcox] and [chief executive] Omar [Berrada] and say, 'We need a lot of players'."We have a plan. If we have to suffer, the club comes first. Of course, we are in a moment where we need points, but we need to find solutions, and we are going to continue with our plan. You can feel in this moment we are going to struggle, but we will see."For all the good Amorim has done at Old Trafford, it does feel like he's made the same "struggle" warning one too many times now. His record of 19 losses, 11 draws and only 14 wins from his 44 Premier League matches in charge makes for miserable reading, and serves as evidence that the "plan" is not working.Even at full strength, that was the case. United have only kept one clean sheet all season, and have dropped points from winning positions against Nottingham Forest, Tottenham, West Ham and Bournemouth over the past six weeks alone.  Senne Lammens has brought a sense of calm between the sticks, but United still have a soft underbelly that is preventing them from challenging the elite again. With Fernandes out, that will be exposed even more. The United skipper not only provides the attacking spark, but also leads by example out of possession, with 96 ball recoveries posted in the Premier League so far in 2025-26, second only to Anderson. Now he is not there to put out fires, there is a risk that Amorim's team will completely capitulate, particularly when the ball is turned over. Newcastle will certainly be smelling blood.Another defeat could put Amorim on the brink ahead of a run of must-win fixtures. The Red Devils face Wolves on December 30 before trips to Leeds and Burnley over the next eight days. That's a favourable run on paper, but it would only be a surprise if they slipped up against Wolves, having thrashed the Premier League's bottom club 4-1 at Molineux just two weeks ago.Leeds are enjoying an upturn and will relish the prospect of causing a Pennines derby upset, while Burnley are never pushovers at Turf Moor. Amorim has to start looking for "solutions" in the transfer market now, or else when Fernandes returns, he could be too late to save his compatriot.