That is the view of pundit Jamie Redknapp.
Mourinho's side were flying in the league before a negative setup at Anfield earned them a 0-0 draw against Liverpool.
Huddersfield then welcomed the Red Devils to the John Smith's Stadium by beating them 2-1 on Saturday.
Mourinho's men now sit five points behind neighbours Man City.
And Redknapp believes the Portuguese boss must focus his energy on getting United firing again.
"Where was the fighting spirit of Manchester United teams of old?" Redknapp questions when discussing the weekend defeat in the Daily Mail.
"Mourinho seems to be wasting too much energy in picking fights with other managers.
"He doesn’t need to do this.
"It seemed obvious that Antonio Conte was the intended recipient when Mourinho moaned last week that some managers ‘cry and cry’ about fixtures.
"Why is Mourinho bothering to wind up Conte? He should be worried about Pep Guardiola and Manchester City, who are threatening to run away with the Premier League."
Mourinho takes his side to Swansea tomorrow for a Carabao Cup tie.
High-flying Spurs then await in the Premier League this Saturday.
And Redknapp believes United have to be back to their best against Mauricio Pochettino's men.
"After enjoying an excellent start, Mourinho has given himself an unnecessary problem," he continued.
"When you keep focusing on the negatives, it filters through to the players.
"With Tottenham at Old Trafford on Saturday, Mourinho must focus on the positives."
