Wes Brown admits Manchester United's defending was not good enough after their shock 2-1 defeat at West Ham.
"We got the lead and we've conceded from two set-pieces that we should have dealt with," Brown told MUTV. "We've let ourselves down.
"If we had scored from the penalty then we would have been 2-0 up. Unfortunately Ronny missed it, but we were still winning 1-0 and we were still in control. We possibly dropped too deep after that, which put pressure on us."
It was a bad way to end the season, but Brown says there is no option but to look forward to the next game against Birmingham City on New Year's Day.
"We need to lift our heads for the match against Birmingham and hopefully go on a run of results. We need to get over this defeat. We'll all be thinking about it tonight, but the next game comes around quickly and we have to forget about it and make sure we do the job in the next match."