New manager Avram Grant insists Chelsea needed to change their approach after a stuttering start to the new campaign.
Grant was installed as boss following Jose Mourinho's shock exit
"We haven't played well this season and the time has come in the last month for a change," said the 52-year-old, who succeeded Jose Mourinho last week.
"We played one game against Birmingham which was fantastic and 20 minutes against Reading.
"There are many things we can improve on and we want to give the supporters a style of football."
Grant, formerly Chelsea's director of football, accepts that his biggest challenge is to get the side hitting the net again.
The players have the quality but we haven't shown it so far this season
"I think scoring goals is the main problem," he said.
"Things have not gone well in the last two months and we have only scored two goals in five games. But I know the problems. The players have the quality but we haven't shown it so far."
Grant, who takes his side to face Hull City in the Carling Cup on Wednesday, added: "The team has had periods for two to three years when Chelsea have played good, but maybe the time has come to change the base a little bit, maybe 20 to 25 per cent."
The former Israel coach, who has taken the manager's job without a contract and does not have the mandatory Uefa pro licence, admits that he won't have long to get things right at Stamford Bridge.
"I know that I don't have long term credit," he said. "Everyone knows in football that even the term permanent is temporary and I just have to do my job."
Mourinho's back-up team all left the club along with the Portuguese coach when he left by mutual consent last Wednesday.
The speed of events has left Grant working alongside Mourinho's assistant Steve Clarke but he confirmed plans were in place to install his own team.
Grant said: "Everything happened so quickly but we are looking for staff that will be good for Chelsea.
"We are still looking but I think in two or three weeks, you will see the arrival of the new staff.
"The previous staff did a good job here but they decided to go with Jose. I understand them. I want to do it as quickly as possible but we want quality and will take our time.
"We are looking in England and abroad. We need a fitness and a goalkeeping coach. We are using people from the academy at the moment and they are doing a good job."
Grant also insists he has the backing of the squad, despite their 2-0 defeat to Manchester United in his first match in charge on Sunday.
He said: "I have spoken with most of them. I want feedback from them on the pitch and when they speak with me.
"They speak with me very well. The injured players are trying to get back sooner than expected..
"I can only judge the players by their actions or the way they speak to me. the way they speak to me was on the pitch on sunday and in training. But Chelsea can be proud of these players they are very professional, have a good attitude and I don't see too many problems."
"When you have 25 players in the squad, sometimes it happens one or two aren't happy, so far I've not seen it and I'm very positive person.
"I expect some will be some happy and some will not but I know it can never be 100% happiness."