Manchester United have seen a difficult time ever since the retirement of the great Sir Alex Ferguson. Quite a few managers have come in but none of them have been able to maintain their position for different reasons.Current Manchester United manager Ole Gunnar Solskjaer has had a considerable amount of time at the club and results are expected of him now. That being said, things haven't been going his way so far.Certain Manchester United players need to be more consistentSolskjaer has struggled with some of his tactics and on-field decisions but a lot of it also comes down to the players. While the likes of Bruno Fernandes, David De Gea, Cristiano Ronaldo and others have stepped up, some haven't shown the same consistency.Some Manchester United players have looked lethargic at times, which hasn't helped Solskjaer's cause. If that changes, it can help United in a big way. On that note, let's take a look at five Manchester United players who should stop being so inconsistent:#5 Anthony MartialClub Brugge v Manchester United - UEFA Europa League Round of 32: First LegThe Frenchman was signed from AS Monaco in the summer of 2015. He was signed to play under then Manchester United manager Louis van Gaal. Anthony Martial was very impressive in his Monaco days, resembling similar to what Thierry Henry did with the French club.This obviously raised a lot of expectations from him and he has now been with Manchester United for more than six seasons. During this period, Martial has had some ups and downs but slowly he's running out of favor with the Red Devils.utdreport@utdreportSolskjær: "I remember there were talks about our forwards last season being the least active and there were stats flying around but Anthony [Martial] is now working really hard for the team and he is a quality, quality finisher." #mulive3:12 PM · Jul 15, 20202773199Solskjær: "I remember there were talks about our forwards last season being the least active and there were stats flying around but Anthony [Martial] is now working really hard for the team and he is a quality, quality finisher." #muliveThe French winger started impressively but faded off with frequent changes in management. Martial had a solid 2019-20 season scoring 17 goals in the Premier League. The Manchester United forward has since lost his way and form and this is not the first time it has happened with the former Monaco winger.With the challenge possessed in the Premier League, a certain consistency is required and with the way things are right now, Martial might soon be out of the club soon.#4 FredSouthampton v Manchester United - Premier LeagueIf there's one Manchester United player who's been slaughtered among the fans, it's Fred. The Brazilian joined the Premier League club in 2018 from Shakhtar Donetsk.While it looked like a promising signing then, it hasn't gone as per plan for both Fred and Manchester United. The central midfielder has provided a good work-rate and energy but has struggled with his positioning and being productive in attack.Manchester United@ManUtd🗣 "Fred's a very good player, a regular for Brazil, which is a mark of his quality," Ole adds."He tackles, he's never afraid and the development he's made since I've been here is great to watch. He will sacrifice himself for the team, that's for sure." 🙏#MUFC | #MUNLIV6:04 PM · Oct 22, 20215358335🗣 "Fred's a very good player, a regular for Brazil, which is a mark of his quality," Ole adds."He tackles, he's never afraid and the development he's made since I've been here is great to watch. He will sacrifice himself for the team, that's for sure." 🙏#MUFC | #MUNLIVFred has been caught making silly mistakes time and again, making the United fans lose patience with him. His partnership with Scott McTominay has been helpful for the Red Devils but with none of them being terrific playmakers, Manchester United are sometimes stuck with a lack of creativity.This season will be defining for Fred's future and it is likely that if Solskjaer is sacked, the Brazilian might run out of favor at United.