Eric Bailly will miss the Super Cup against Real Madrid on 8 August and United's first Champions’ League group match, the defender has been hit with a three-match ban for his red card against Celta Vigo in the Europa League.
The 23-year-old was sent off after a mass brawl in the semi-final on 11 May and missed the final against Ajax, which United won 2-0.Related: BREAKING: Man United defender handed three-match ban by UEFA
However, the suspension has now been extended to include two more games.
The Ivory Coast international's case does not qualify for an appeal because European football's governing body UEFA only overturns decisions made by the referee in cases of mistaken identity.
Bailly was sent off for a swipe at Celta's former Manchester City striker John Guidetti, with Facundo Roncaglia dismissed for retaliating.
Manchester United defeated Real Madrid in the International Conference Cup on penalties in the United States on Sunday night.
However, it will be a different ball game when they clash for the coveted trophy next month, notably, absentees in the Real Madrid squad will be present especially the likes of Cristiano Ronaldo and Sergio Ramos.
Aside Eric Bailly, Manchester United might also be without the services of Jesse Lingard and Juan Mata.