A 1-1 draw to relegated Huddersfield Town on Sunday ensured the Red Devils would not be playing Champions League football next season.
The result at the john Smith’s Stadium means United have too much ground to catch up on Tottenham Hotspur, Chelsea and Arsenal.
Finishing fifth or sixth would mean a return to the Europa League – a competition Jose Mourinho won in 2017.
But, depending on who wins the FA Cup final on May 18, United could be starting their season as early as July.
City could be looking to complete a domestic treble against Watford at Wembley, with the Hornets aiming to win a first piece of silverware in their history.
Whoever wins gets an automatic place in the Europa League. However, as City have already qualified for the Champions League, a victory for them means the European spot would go to the seventh-best side in the Premier League.
That means Wolverhampton Wanderers or Leicester City will be in with a chance of qualifying for the Europa League.
But, if Javi Gracia’s men upset the odds to win the world’s oldest club competition, they would automatically be sent into the group stages.
That would be terrible news for whoever finishes sixth in the league table (currently United) as it means they would have to go through the qualifying stages – starting on July 25.