Jose Mourinho admits he has to change the culture at Manchester United before the club can return to the top of English football.
United claimed a comfortable 3-1 victory at struggling Swansea to secure a first win in five Premier League games and move back into the top six.
But Mourinho, who was serving a one-match touchline ban after accepting two Football Association misconduct charges, suggested after the game that players had been "influenced by some culture issues" before his summer arrival at Old Trafford.
Mourinho told Sky Sports: "The players believe in me and I believe in the players. That has never been the problem.
"I want to say they were influenced by some culture issues, influenced by a situation that has been going on for a few years.
"There is a difference between the brave, who want to be there at any cost, and the ones for whom a little pain can make a difference.
"Of course, it is not just the players, it is the players and the people that surround the players."
Mourinho made five changes from the side which had been held to a goalless draw by Burnley in their previous league game.
Phil Jones and Michael Carrick made their first league starts of the season with Luke Shaw and Chris Smalling among those missing out.
Mourinho told MUTV before the game: "Smalling doesn't feel that he can play 100 per cent with his pain. Luke Shaw told me this morning that he was not in the condition to play so we had to build a defensive line."
And at his post-match press conference, Mourinho said: "We have players with problems, players on the pitch with problems.
"Every sport - and I know that because I have friends from other sports who play at the highest level - you play when you are not 100 per cent.
"I have a friend who is a big tennis player and he remembers more the times he plays in pain than without any pain.
"That's what I mean, to compete you have to go to the limit.
"It is a cultural thing for some. But that's not my culture. And more than me, Man United's (culture)."
United were 3-0 up inside 33 minutes as Zlatan Ibrahimovic scored twice to add to Paul Pogba's brilliant strike.
Ibrahimovic had not scored in the league since September 10, but his 609-minute goal drought ended when he drove home low from 20 yards and then added another after being fed for the second time by Rooney.
Mourinho said: "I used to say that a striker that does not score goals and does nothing else is one player less.
"A striker that doesn't score goals but does everything else is a very important player for the team.
"He was not scoring goals but he was doing everything else."
Swansea remain one place off the foot of the table and have yet to win under new manager Bob Bradley.
The former United States boss has lost three and drawn one of his four games in charge.
And the mood inside the Liberty Stadium threatened to turn ugly as supporters vented their anger at board members who sold the club to new American owners in the summer.
"If the fans are angry, I understand that," Bradley said after Mike van der Hoorn's 69th-minute header had provided scant consolation.
"We didn't do enough to win them over. They had every right to be angry.
"It's a tough spot there is no two ways about that. We understand very clearly where we are and there is no hiding from that.
"But we have to keep everyone going and hopefully get some results."