Harry Maguire believes
Manchester United are being "targeted" at set-pieces after their disappointing 2-0 defeat to Wolves.
United left Molineux with ten men and zero points after goals from Matheus Cunha and Hwang Hee-chan sealed the victory for the hosts.
Cunha's opener in the 58th minute came directly from a corner, marking the second time in just eight days that United have conceded such a goal.
Maguire expressed concern about his team's growing vulnerability in these situations.
He said: "To concede again, especially the first goal of the game, set-plays are so important in football matches.
"They decide games, a lot of the games when they're tight and they're 50/50. The first goal has been a set-play far too many times against us, and it's disappointing."
Set-pieces have been a recurring issue for United this season. In addition to Cunha's goal, they have conceded from set-pieces against Arsenal, and Tottenham's Son Heung-min even managed to score directly from a corner.
So far, United have conceded ten goals from set-pieces this season, excluding penalties.
When asked how the team can address this problem, Maguire emphasized the importance of hard work: "Work, work, work more on the training pitch. I think teams now are maybe targeting our areas of set-plays.
"The strange thing is, I don't feel like we're conceding many chances from them. They've had a few set-plays tonight, and we've dealt with them really well, and they've gone and scored from one.
"I think it's hard work, keep the belief, things will change. I know that. We have players who can defend the box well. They will change, we've just got to stick together."
The defeat leaves United with a tough task ahead as they prepare to host Newcastle next, but their lineup will be weakened by key absences.
Bruno Fernandes is suspended following his red card against Wolves, and Manuel Ugarte will also miss out after accumulating another yellow card.
Manager Ruben Amorim acknowledged the challenges but remained focused on moving forward.
He said: "Of course, when you lose, when we don't win, it's a step back. It was really hard with the sending off.
"The goal was similar against Tottenham. Then, we tried. Even with one less guy, we tried, and I think we were near something, but then Wolves scored the second one.
"Then, in the end, we tried everything, and the transition was 2-0. For us, let's continue."
As United struggles with set-piece vulnerabilities and key suspensions, their resilience will be tested in the coming fixtures.