Avram Grant admitted Tuesday night's Champions League bore draw at Olympiacos was Chelsea's worst European performance since he took over from Jose Mourinho.
The Blues stumbled to a goalless stalemate in Athens in the first leg of their last-16 tie.
Grant, who made 11 changes and left skipper John Terry and Frank Lampard on the substitute's bench, was disappointed with his side's display, while at the same time expressing satisfaction with the result.
When asked if it was their worst European performance since he took charge in September, the Israeli said: 'Yes, it is a game in which we played less well.
'I am pleased with the result. A draw away from home is good. But the performance could have been better. We didn't create many chances.
'But Olympiacos are a very well organised team and it is not easy to play against them.
'We hope to improve in the return leg.'
Grant refused to say whether Lampard or Terry would be included in the starting line-up for Sunday's Carling Cup final against Tottenham at Wembley but maintained that he is ready to continue making difficult decisions about his side.
Grant added: 'I am always asked about the players I leave out of the team but I am the manager and it is my job to make these decisions.
'I will continue to make them for the benefit of the team and it will happen again and again.'
Grant was clearly rocked by Chelsea's inability to break down a relatively unadventurous side that offered little in attack.
Didier Drogba looked distinctly out of sorts and Grant's attempt to win the game by adding Nicolas Anelka, Salomon Kalou and Lampard in the closing stages was very much too little too late.
Olympiacos coach Panagiotis Lemonis was happy enough with the result and insisted he would not be changing his style for the return leg at Stamford Bridge in a fortnight's time.
Lemonis said: 'We always knew it would be difficult for us once we got through from the group stages but we found Chelsea very strong in defence.
'We will go to London and try to do the best we can but we know it will not be easy against a team with such quality.'