The manner of Chelsea's fightback at Old Trafford left United clinging on, and Carrick admitted that a replay is by no means the worst outcome for Sir Alex Ferguson's side.
"We've mixed emotions in some respects," he said. "We're completely disappointed, from the position we were in, not to finish it off - there are no excuses for that - but at the end we could be out of the competition with the opportunities they had, especially the save David made from Mata.
"David has stepped up there at a big time in the tie and kept us in it. We can be very thankful for that because we could have been out of the cup. It just shows his quality. When you need him, he's there. We're taking the positives, really: we're still in the cup, we've got another chance at it so we move on."
"[Stamford Bridge] is a tough place to go because they're a good team. Of course we'll go there positive because it's in our nature. We go there believing we can win."
- Michael Carrick