Jose Mourinho admits he still has lots of work to do before he perfects Chelsea's new-look formation.
Mourinho starts his bid for a hat-trick of Barclays Premiership titles against Manchester City on Sunday.
His team were beaten 2-1 by Liverpool in the FA Community Shield yesterday and he claims they are less than halfway to finding their best form.
Mourinho said: 'We have to keep working. We are not in the same moment as other teams. You need to work. You need to change things. We want to play a different way. We need sharpness we do not have in this moment.'
Chelsea have brought Michael Ballack, Andriy Shevchenko, Salomon Kalou and Mikel John Obi into the first-team squad this summer and Ashley Cole could soon join them.
After the Community Shield defeat, Mourinho was asked why he felt the need to make such drastic changes to a winning team.
He said: 'I have changed things as I like to play a different way. I like to win matches by playing a different style. When you have strikers with our dimensions, you have to use these people in this form.'
The Chelsea boss claims his team are so far off the pace because his international stars needed to rest after the World Cup.
He is also annoyed to be losing all but four of his senior players to international duty this week when he would prefer to be preparing for the City game.
Mourinho said: 'On Sunday, we will be only 40% but I am not worried because the competition is over 10 months. If something happens in the first two weeks, maybe you lose a game or four points, but that's why I like competitions of 10 months.
'I will train this week with two goalkeepers and two Portuguese players because they are the only country not playing. I have to say this is intelligent. They realise players should be with their teams before the season starts not with their national teams.'
