The latest apparent distraction are empty seats.
United has won 13 and lost six of its 24 home games in all competitions this season. In contrast, it won 17 and suffered three defeats from 26 matches away from Old Trafford.
As a result, the club has changed the color of the seat coverings in Old Trafford from red to black in an attempt to improve matters.
“We’ve looked into this. There shouldn’t be a reason, really, but some of the players mentioned that, in the split-second decision, you have to look over your shoulder to see if your teammate is there or not then the red shirt is on a red background with red seats.
“Then again if you have a 4-0 advantage [as against Sociedad], you don’t really have to win that game: 0-0 was a good result. Then in the first game against Milan, we conceded in the last minute.
“I still think we’ve played some good football at home, [though] we started off badly [in the Premier League] with three defeats to Palace, Tottenham and Arsenal, but we’ve improved.”
The decision comes almost 25 years to the day since former manager Alex Ferguson ordered his players to change their grey shirts at halftime in a match against Southampton because they were struggling to identify each other.
United host Granada in the Europa League quarterfinal second leg on Thursday with a 2-0 lead.