Rio Ferdinand admitted Manchester United had been punished for carelessness after letting a two-goal lead slip in the FA Cup quarter-final against Chelsea.
A 2-2 draw at Old Trafford leaves the tie unresolved with the winners to face Manchester City in the semi-final - though first they have to find a suitable day to hold the replay.
Ferdinand, who could face action from the Football Association after an off-the-ball altercation with Fernando Torres, told MUTV: "We gave them the impetus to claw their way back into the game. We played some great football at times but were so careless at times. If you are careless you are going to get punished. That was the case.
"But we are still in the cup. Wembley is waiting for one of us to go through and hopefully it is us.
"We go to Stamford Bridge for the replay with confidence. We have the tools. We have been there before this season and done well and with the squad we have we don't fear going anywhere."
United boss Sir Alex Ferguson said his team paid for their efforts against Real Madrid in midweek.
"We're lucky to be in the cup. We just ran out of legs and Chelsea were far the better team in the second half," he said.
"But I can't be critical of my side because the running they had to do on Tuesday night, against a really top side in Real Madrid, had its bearing on today's result, no doubt about that.
"The two full-backs, Rafael and Patrice (Evra), are knackered and the two central midfielders tired badly. We kept giving the ball away and it made it a long day for us, going from one penalty box and back to our own."
Ramires and Eden Hazard levelled the game for Chelsea following early goals by Javier Hernandez and Wayne Rooney. United lost Nani with a hamstring problem at the end of the first half but Ferguson said the injury was not "too serious".