Ole Gunnar Solskjaer has challenged his Manchester United players to raise their game against the Premier League's "lesser teams".
United picked up back-to-back wins over Tottenham and bitter rivals Manchester City in the space of four days to revive their domestic campaign.
The Red Devils also beat Chelsea 4-0 on the opening day of the season and are the only side to have taken a point off leaders Liverpool this term.
However, they have lost to two teams in the bottom six and drawn against two more struggling sides in Southampton and Aston Villa.
With games against bottom-half teams Everton, Watford and Burnley to come in three of their next four league outings, Solskjaer admitted a change of mentality may be required.
"If it's a mental thing, then we can sort it out," he said, according to several British newspapers. "We'll work with the mentality of the boys.
"For me, it's been very much about margins in those games. Some freak results that we can't control.
"But if you look behind the results, I'm not as negative as you are. I'm not so worried, so concerned. If the boys are then telling me they can't get up for these games then we've got a problem.
"Then I've really got to work with them because, when I played, that's how we won the league.
"We never gave points away against the lesser teams, the not-so-good teams. The Premier League is difficult – if you don't have that mentality you won't get results.
"You've got to earn the right to win. Sometimes you've got to earn it by passing quicker, winning the ball back – there are different ways of winning games of football."
A key part of United's success against Tottenham and City has been the improved form of Jesse Lingard, who was reprimanded earlier this year for a video posted on social media.
Lingard started both matches and Solskjaer is delighted with the way the United youth product has bounced back of late.
"He's Man United through and through," Solskjaer said. "He's a red, he's got a great attitude and a great work rate.
"Every one of us have things to deal with on the pitch and off the pitch and what he has had to deal with, that will be between us. It's great to see him back.
"You can criticise anyone about anything but for me as a manager, I have to look after these boys in the good and the bad times.
"It's great to work with him. I had him in the reserves, gave him his debut against Burnley. It's good to see him back to his old self."