Harry Maguire says Manchester United's players have to stand up and be counted by immediately bouncing back from their unacceptable defeat to rock-bottom Sheffield United.
Ole Gunnar Solskjaer's men were stunned by Chris Wilder's Blades at Old Trafford on Wednesday night when substitute Oliver Burke's heavily-deflected strike secured a shock 2-1 win for the visitors.
Maguire had cancelled out Kean Bryan's opener, but Manchester United failed to build on his second-half header as his former club celebrated just their second Premier League win of a wretched season.
"We have great belief," the United skipper said. "At half-time we knew we didn't perform well in the first half but felt like we still had belief that if we scored the next goal we would go on to win the game.
"We scored the next goal, it was an important goal and we never found anything extra to push, found that little spark, that inspiration. Something was missing.
"We'll work on it, we've got to improve. We know that it's not good enough for this club.
"We've got to win games, especially at Old Trafford against teams that are where they are in the league.
"For sure we've got to improve."
Maguire was fuming about the decision to allow Bryan's opener given Billy Sharp shoved David De Gea as the corner came in, just as he was angered to be called for a foul that saw an Anthony Martial leveller ruled out.
But those decisions could not mask the poor display that saw them lose in the Premier League for the first time since November 1 against Arsenal, United's opponents when they return to action on Saturday.
"It's the best thing possible," Maguire told MUTV ahead of the trip to the Emirates Stadium.
"When you do get a defeat, there's nothing worse than waiting time to get back out on the pitch to play and put things right.
"The boys are devastated in there, if I'm being honest. It's a really quiet dressing room. The boys are so disappointed.
"We didn't expect it. We came into the game confident, but we've got to pick ourselves up. Tomorrow is a new day.
"We are still disappointed, it hurts, but Saturday is a big game and we've got to bounce back.
"It's all good and easy when you're winning football matches and you're playing well, but now it's time to stand up, be counted.
"When you get kicked down, it's how quick you bounce back and Saturday's a big one and we've got to go and get three points."
While Solskjaer prepares his side for a trip to the Emirates Stadium, the Blades will be back in Manchester to take on Pep Guardiola's table-topping City side on Saturday.
It is another big ask for embattled Sheffield United, but Wilder's men will take great confidence from Wednesday's win.
"The players are jumping about in there which they deserve to, because it's been a tough old season," the boss said.
"We'll bring everyone back down to earth tomorrow to go again at the other side of town. I'm delighted for the players because they've gone through a hell of a lot this season.
"We talked about big moments which we took.
"The second goal was a great reaction to the equaliser, to come back and stick our noses in front again, and it's a great moment for us."
