The Red Devils will look to end a four-game winless run when Manchester United host Claudio Ranieri’s Fulham side.
Manchester United haven’t won a Premier League game since a 2-1 victory over Bournemouth at the start of November.
The Red Devils lost 3-1 to Manchester City in the derby before successive draws with Crystal Palace, Southampton and Arsenal.
Mourinho’s side came from behind twice to salvage a 2-2 draw with their bitter rivals Arsenal to keep their faltering top-four challenge alive.
Fulham have collected four points from three games since Premier League winner Ranieri took over the reins last month.
Only Chelsea FC have managed to beat Fulham since the Italian took charge.
Former Arsenal midfielder Merson is tipping Manchester United to make a much-needed return to winning ways against Fulham at Old Trafford on Saturday.
“I see a return to winning ways for Manchester United against Fulham at Old Trafford,” Merson told Sky Sports.
“However, if they do not win this game Jose Mourinho will do well to keep his job come Monday. If they can’t beat Fulham at home where are they going?
“At the moment we are talking about it being a feat if they get into the top four so this is a must-win game. If they don’t win the game I would be shocked if Mourinho was there on Monday.
“I don’t see it coming to that though because if there was one team you’d pick to play it would be Fulham. They did alright against Chelsea but it was just okay, they were never going to win. Fulham have improved under Claudio Ranieri since his arrival but they have to start winning games soon. It won’t be this weekend though.”
Manchester United have only failed to beat Fulham in two of their 23 meetings to make the Red Devils clear favourites to pick up three points.
The 20-time English champions’ only loss to Fulham at Old Trafford in the Premier League occurred in 2003 when the Cottagers eased to a surprise 3-1 victory.
Manchester United are in eighth place and eight points adrift of fourth-placed Chelsea FC.
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