London - Jose Mourinho has warned Arsene Wenger that Chelsea are back in the groove as the Premier League champions look to extend their revival in Saturday's showdown with London rivals Arsenal.
Mourinho's side are languishing just above the relegation zone following a miserable run of one win from their first five matches, but the Blues boss is confident his players are beginning to rediscover their swagger after a 4-0 demolition of Maccabi Tel Aviv in midweek.
That vibrant opening to their Champions League campaign was a stark contrast to the doom and gloom that surrounded the club after their worst start to a season since 1988.
Already trailing leaders Manchester City by 11 points and fourth placed Arsenal by six, a third successive league defeat this weekend could leave Chelsea's title defence in tatters.
Yet Mourinho expects the challenge of taking on a title rival will draw a powerful performance from his team against an Arsenal side reeling from their surprise Champions League defeat at Dinamo Zagreb.
"We come with a different feeling. We can wake up with a different state of mind," Mourinho told Chelsea TV.
"Saturday is a big match, it's a great rival. This result can put us in a better situation.
"We had too many bad results. We couldn't have this one on top of it."
Mourinho has been quick to dismiss claims of a rift with captain John Terry, one of several players dropped for the Maccabi clash.
But Mourinho looks an agitated figure at present and locking horns with old rival Wenger is likely to keep him in a waspish mood, especially since he is still smarting from losing to the Arsenal chief for the first time in 14 meetings in the Community Shield last month.
Facing Chelsea on the back of a European setback is hardly ideal preparation for Arsenal, who haven't scored in their last four league meetings with the Blues.
However, Gunners forward Theo Walcott is adamant his team will shrug off that setback in time to add to the Mourinho's problems at Stamford Bridge.
The Gunners have been solid if unspectacular in the league so far and Walcott, who came off the bench to score against Zagreb, said: "Everyone will be very disappointed but we need to move on now.
"We have had setbacks before and have managed to bounce back from them. We have got a big, important game at the weekend.
"The manager will make sure that it's put to bed in the changing room and that it will stay there. We need to reflect on this game and move on quickly."
The match kicks off at 13:45.