United have collected just six points from their opening six Premier League matches, their worst start to a league campaign since 1986-87, when they managed only four points.
Carrick, who took charge in January following Ruben Amorim's departure, acknowledged the disappointment but urged his players to remain focused as they look to turn their season around.
"We expected a lot more," Carrick said on Monday. "I knew there was going to be a period where it became stickier. That's part of it. It's a journey."
The United boss also pointed out that Atletico have experienced difficult periods despite their success, insisting his team must learn to handle the pressure rather than panic.
"I understand people thinking it's a disaster, but that's not in our mindset. You've got to be able to deal with it," he said.
Carrick believes defensive mistakes have contributed to United's struggles and warned that small details could prove decisive as they attempt to regain consistency.
"The last three goals we've conceded, we could have done something about them. That can be the difference," he said.
He also stressed the importance of rewarding the supporters who have continued to back the team during a frustrating period.
"The fans are there, and we've got to give them something. We will come through it," Carrick added.
United will look to build on their emphatic 4-0 victory over Azerbaijan's Sabah FK in their opening Champions League match. Atletico, meanwhile, head to Old Trafford after losing 2-1 to Liverpool in their European opener.
Carrick has received a boost with Dutch centre-back Matthijs de Ligt returning to the travelling squad after a lengthy absence with a back injury that dates back to November 2025.
However, United remain concerned about the fitness of midfielder Kobbie Mainoo and left-back Luke Shaw, who both picked up injuries during Saturday's 1-1 draw at home against 10-man Tottenham Hotspur.