Sir Alex Ferguson has admitted Manchester United cannot afford to lose games to the likes of Burnley if they are to retain their Premier League title following Wednesday's shock 1-0 defeat at Turf Moor.
United lost to a Robbie Blake goal against the newly-promoted Clarets and afterwards Ferguson offered no excuses.
"I'm sure we'll get a response (at Wigan) on Saturday, but we're all disappointed because it was a bad result," said Ferguson.
"It was a terrific pitch so that's no excuse. We just should have done better with it. We didn't play well but that can happen.
"We usually take time to get going every season - sometimes it's October before we get to our best form - but, yes, we shouldn't be losing these games."
Ferguson felt that had Michael Carrick converted a 43rd minute penalty after Patrice Evra was felled then the champions would have gone on to win the game.
He added: "I think we'd have won the game if we'd scored that. We'd have composed ourselves and won, I think.
"Instead, in the second half we got harried with our passes and made a couple of bad decisions. That can happen.
"We should have done more with the chances we had and the possession we had.
"But in fairness to Burnley they had a good spell too and caused us a lot of problems."