The Red Devils suffered a first defeat under interim manager Ralf Rangnick with a 1-0 Premier League home defeat by Wolves on Monday night.
United’s meek performance was followed by reports about a poor mood inside the dressing room, and on the back of being branded “a bunch of whinge-bags” by former defender turned TV pundit Gary Neville during half-time of the 1-1 draw at struggling Newcastle.
Maguire knows the players must do better, as they prepare to return to action in the third round of the FA Cup against Aston Villa on Monday night.
“I’ve obviously seen a lot of criticism and a lot of is absolutely justified, but for me, with this team, it shouldn’t need criticism to motivate players,” Maguire told national newspapers, in an interview published on www.manutd.com.
“If players of this quality aren’t motivated to play for this club when they pull the shirt on, then there’s something wrong.”
I’m sick of repeating myself but it can’t continue like this - we need to go on a proper run, starting Monday
Maguire added: “From what the fans and ex-players have said, we get it.
“As I just said, a lot of it is justified and we all have to take massive responsibility, myself as captain as much as anyone, if not more. We’ve got to start playing well and winning.
“This team finished second last year and we have a better and bigger squad this year, so we have to show the right attitude.
“We have big players in the team; leaders. I’m sick of repeating myself but it can’t continue like this – we need to go on a proper run, starting Monday.”
Maguire is expecting a reaction, but played down suggestions of disharmony in the dressing room.
“We are all angry and want to do our best, which has probably come across on the pitch at times, but the team spirit is good, despite what people say,” the England defender added.
“Being a professional footballer, you have to take criticism on the chin and react well to it.
“At the same time, you have to ignore the outside noise sometimes and just get your head down (in training).
“We know if we can put together a run of results then everything else takes care of itself.”
Maguire maintains the squad have been left in no doubt of what standards are expected.
“I am the captain and leader in the dressing room and I’ve had private conversations with the players and the management which will remain private,” he said.
“Make no mistake about it, I’m here for the fight and I know my team-mates are. I expect them to be and if they’re not then – like I said – there’s something wrong.
“We have a big squad. Of course, not all players will always be happy as they are not playing but that’s football and we all have to remain professional.”
Former Leicester defender Maguire added: “I came here to win titles. I could have signed elsewhere, but I wanted to be at United and help get them back to the winning ways that the club had in the Sir Alex (Ferguson) era.
“It will come if we all stay together. I grew up idolising the likes of Wayne Rooney, Rio Ferdinand and Nemanja Vidic – and I want to repeat what they achieved.
“I am privileged to be captain and I’ve got a responsibility to lead the players and turn things round.”