Harry Maguire says Manchester United must take a hard look at themselves after Tuesday's loss to RB Leipzig.
The defeat means United have been eliminated from the Champions League and will now compete in the Europa League.
Speaking after the game, Maguire said: "We started the game too slow. It wasn't good enough. The first 20 minutes we weren't at it. They put two balls in the box and we failed to deal with them.
"We have to look at ourselves, we gave ourselves too much to do. You've seen how close we came at the end but we started too slow and we can't keep falling behind.
"We said on Saturday at half-time, 2-0 down, the next goal is crucial and we said it again tonight. They made it 3-0 and the task becomes even bigger. The third goal proved to be the crucial one but even three down we came close at the end.
"I don't want to look at excuses. We have to go out and be aggressive, win balls. That's the basics. If you can't defend crosses you're going to lose games. I don't want to look at shape - it's not an excuse.
"It's a tough group but we felt we should get through. That's the standards of this club. I'm gutted for everyone, we worked so hard to reach this competition. No matter what group we got it would be tough. We have to do more."
