Juande Ramos admits Tottenham will have little chance of Carling Cup glory against Chelsea without significant improvement on this week's European performance.
Spurs warmed up for Sunday's Wembley showpiece with a nervous aggregate victory over Slavia Prague in the UEFA Cup.
'The truth is if we play like we did against Slavia, then we are not going to win very often,' said head coach Ramos.
'But you have to remember this is the same team that beat Arsenal three weeks ago, so we do have possibilities of winning.
'It's true, though, the performance against Slavia wasn't the best - and we'll have to improve to be able to beat Chelsea.
'Every game is different. We know Chelsea are a good team and probably go into the final as favourites because they are higher up in the league table as us.
'But anything can happen in football, and we need to play with the maximum level of concentration.'
Ramos has earned a reputation as a knockout specialist after consecutive UEFA Cups and a Copa del Rey with Sevilla.
He has already masterminded victory over Arsenal in the Carling Cup semi-final and came within seconds of defeating Manchester United in the Barclays Premier League.
The United result saw him praised by Sir Alex Ferguson, and he has been tipped as having the potential to be one of the top managers in England.
However, he added: 'That's not something that's up to me to judge.
'It's tremendously satisfying that people are happy with the work we've done, the progress we've made.
'We've made our position in the Premier League a lot healthier than it was; we're having very good runs in the cups, which is very satisfying, but it's not up to me to judge how good I am.
'It would be absolutely magnificent to win a cup, particularly because it would bring tremendous happiness to the club - who need a trophy.'
Paul Robinson looks favourite to start in goal against Chelsea after returning to the starting line-up against Slavia and keeping Spurs ahead on aggregate last night.
Radek Cerny, in goal for the previous 10 games, said: 'I will be disappointed, like any player who doesn't make the first team. We are playing a big final at Wembley and against Chelsea, and I would love to be out there.
'But the most important thing is that Spurs win, and I will still get to be at Wembley for the first time.'
Captain Ledley King has been rested since the semi-final to get him prepared for Wembley.
Ramos said: 'I'd like him to always play, but his condition has not allowed it.'
There was a slight injury concern when Pascal Chimbonda picked up a knock against Slavia, but first impressions were that it was not serious.