Chelsea manager Luiz Felipe Scolari was left stunned by their shock Carling Cup exit at the hands of Championship side Burnley but had no regrets about making wholesale changes to his side.
Scolari left six regular first-team players out of his starting line-up and then watched Burnley put them out of the competition in a dramatic penalty shoot-out.
Didier Drogba put Chelsea in front in the 27th minute with his first goal of the season but Burnley substitute Ade Akinbiyi levelled with 20 minutes of normal time remaining.
The tie ended 1-1 after extra-time but Burnley goalkeeper Brian Jensen, known as 'The Beast', saved spot-kicks from Wayne Bridge and John Mikel Obi to dump the Premier League leaders out of the cup.
''The players are disappointed because they lost a competition,'' said Scolari. ''They wanted to win this game but now it is time to work for Saturday's game.
''We had all the information about Burnley to win the game. But what happened is similar to other games and we made many mistakes in front of goal. If we had had more quality in front of goal we would have won this game.
''I kept some players out because they have played a lot of games but it was still a side that could have won this match. We have lost one competition. This is not normal for us. We want to win all the competitions but we have lost one and we need to understand this.
''I am not angry with the players because they tried their best. If they make mistakes maybe it is because I have not given them good lessons. The players tried to do their best.''
Victorious Burnley boss Owen Coyle said his side had deserved their sensational victory and a place in the last eight as a reward for all their hard work and fantastic team spirit.
And he paid tribute to goalkeeper Jensen for pulling off two superb penalty saves to win the tie.
Coyle said: ''To come to Chelsea who are top of the Premier League, favourites for the Champions League and one of the elite clubs in the world, and win the game shows the magnitude of effort put in by the players.
''It would have been very easy to hide but I felt we started well. Drogba's goal was class because he is a world-class player. The pressure was all on Chelsea because they were expected to win comfortably.
''Brian has been outstanding all season and I felt he would stop a minimum of one penalty. He's worked hard in training but we didn't practice penalties as who would have thought we would be in a penalty shoot-out?
''The spirit and work ethic of the players was there for all to see. Burnley has a population of 70,000 and to bring over 6,000 fans to Stamford Bridge with the way the financial situation is in the world, was great. This will give the town a big lift and we are delighted for the fans.
''We wanted to commit players forward. It is all too easy to put 11 players behind the ball so I felt we had to push players forward at every chance. Goalscorer Ade Akinbiyi is a model professional and even when he is not involved he is helping and supporting the other players. When he got on he led the line well and that was the turning point for us.
''In terms of scalps, they don't come much bigger than Chelsea. To come to Chelsea, an elite club, and knock them out of the cup, is a great moment.''