Gary Cahill has acknowledged Chelsea must improve swiftly after a less than ideal beginning to Jose Mourinho's second spell in charge at Stamford Bridge.
The Blues are winless in four matches after their worst start to a Barclays Premier League campaign in 10 years and on Wednesday night were beaten 2-1 by Basle in their Champions League Group E opener.
Saturday's west London derby with Fulham is an opportunity to make amends as Mourinho's men bid for a first victory since the defeats of Hull and Aston Villa at the start of the season.
"It's not a disaster but it's not ideal," said Cahill, on chelseafc.com, of the Basle loss.
"A club like this wants to win the majority of games it plays.
"That's the expectation. It's a blow but it's not the be all and end all.
"We need to win our next game now, as simple as that. The manager will stress that.
"We've got the squad to do it, we need to go on now and get back to winning ways on Saturday."
Following a draw at Manchester United, the penalty shootout loss to Bayern Munich in the European Super Cup and last Saturday's defeat at Everton, Chelsea were expected to dispatch Basle, whom they beat en route to winning the Europa League last term.
However, the Blues are now playing catch-up in a group which also features Steaua Bucharest and Schalke, 3-0 victors over the Romanians last night. Next the Blues play in Bucharest on October 1.
That Basle ended Chelsea's near 10-year, 29-match unbeaten run in the Champions League group stages made the result all the more remarkable, but Mourinho's side did not deserve their half-time lead courtesy of Oscar's goal and the Swiss side's first win in England at the 11th attempt was only fair.
"It's a big shock really," added England defender Cahill, who was culpable for loose marking which led to Marco Streller's headed winner nine minutes from time.
"We gave them a bit too much room all over the pitch but first half, we looked like we were in control of the game.
"In the second half we didn't quite step it up that level and we paid the price for it.
"We played against them twice last year and they're a very good side.
"The onus was on us to step it up and we didn't quite do that. At this sort of level we get punished and we're obviously disappointed.
"We were in control at 1-0 up, we knew we could go up a level. I'm repeating myself but we didn't do that and that's what cost us the game."
Cahill accepted Chelsea's defensive performance should be assessed closely.
"You can always do better, you can always analyse goals and have a look, definitely," he said.
"The back four, goalkeepers, individuals. We'll have a look at that."
Also to be scrutinised will be Mourinho's methods, with John Terry left on the bench for a second successive continental clash and Juan Mata brought on only for the final quarter of the fixture, despite the Blues lacking the guile to unlock the Basle defence for a second time.
Mourinho's 62-match unbeaten home record in the Premier League will be at stake when the Cottagers visit this weekend.
Fulham have one top-flight win this term and should not be too much of a concern, but Mourinho must find a way to rediscover the scintillating football on show in his first competitive fixture, at home to Hull - and, at times, against European champions Bayern Munich in Prague - if Chelsea are to challenge for major honours this term.
Mourinho has emphasised the youth in his side, but the likes of Marco van Ginkel, Oscar and Eden Hazard have been recruited at great expense, and there is still an experienced core including Frank Lampard, Terry, Ashley Cole and Petr Cech, survivors of the Portuguese's hugely successful first spell in charge.
Samuel Eto'o, a Champions League winner with Barcelona and Mourinho's Inter Milan, has also started slowly and was at times invisible against Basle on his second appearance, while debutant Willian lacks match practice.
Despite lacking a cutting edge up front, Mourinho insisted he is happy with his strike options, which include Fernando Torres and Demba Ba.
The trio, and Chelsea, will be bidding for a boost of confidence against their neighbours this weekend.