Juande Ramos insisted his Tottenham side could bounce back in the second leg of their Uefa Cup tie following the 1-0 defeat to PSV Eindhoven at White Hart Lane.
Spurs started slowly and fell behind when debutant Gilberto gifted possession to Jefferson Farfan and he finished spectacularly from the edge of the area.
PSV threatened on the break throughout as Tottenham struggled to break down the Dutch team's resistance.
Ramos admits his players will have to improve considerably to stand any chance of making it through to the quarter-finals, but maintains the tie is far from over.
"Of course I didn't like the result but we still have a second leg to play," said the manager.
"When you lose by 1-0 it is not too bad but we will have to play a lot better in the second leg."
Ramos also refused to single out Gilberto for blame, even though he took the Brazilian off at half-time.
He explained: "Every footballer makes mistakes. We have to support him and help him recover his best level.
"I didn't substitute him because he made a mistake at the back. He has been injured and needs to play many more games."