Too many Aberdeen players did not play at their best in the Scottish League Cup 2-1 by Dundee United, Dons boss Derek McInnes claims.
The cup holders took a second-half lead through Donervon Daniels on his debut but were knocked out by headed goals from Callum Morris and Nadir Ciftci.
"To win semi-finals you need a level of performance," said McInnes.
"You need 'x' amount of players to turn up and bring what they are capable of and I don't think we had that."
The result is desperately disappointing for Aberdeen, whose fans at Hampden outnumbered those in tangerine by about two to one.
Last March they had celebrated their first cup win since 1995 when they beat Inverness on penalties to lift the League Cup.
And when the impressive Daniels, on loan from West Brom, ran in to the box and directed a looping header beyond Radoslaw Cierzniak four minutes into the second half, things were looking rosy for the Reds.
Their lead, though, did not last long as Morris hammered in a close-range header and Ciftci was left unmarked to nod in the winner six minutes from time.
"We didn't play particularly great. I don't think we had enough good performers on the day to win it," continued McInnes.
"After going in front at the start of the second half for five or 10 minutes we were quite composed but in the build-up to their goal we gave the ball away too loosely.
"We've lost a scruffy second goal. We've come out thinking that we've cleared our lines but we hadn't properly cleared it at the edge of the box. Whether it's offside or not, I don't know.
"Our back four played well; as a unit they were very solid, but I don't think we had too many more.
"We lost a goal from a set play, which was disappointing, but I think the response was decent.
"We should probably have scored from (David) Goodwillie's header and we had a goal chopped off, which I haven't seen again. My first reaction was that it was a goal that should have stood.
"We wish Dundee United well. They were always a threat with their pace."
Daniels' performance augurs well for the rest of the season, but his ability came as no surprise to the Pittodrie boss.
"He was excellent", McInnes said of the 21-year-old centre-back.
"He just played the way he's trained all week. He's a boy that we have watched for a period of time now so I always felt confident.
"My only concern was that he hadn't played a game with us before going into a game of this magnitude. He should have been part of a winning side with that performance."