Following a perfect start to the Premier League season, Chelsea opens its Champions League campaign at Slovak champion MSK Zilina.
Chelsea scored 17 goals in the first four league games while conceding only one, and newcomer Zilina faces a difficult task to stop the English champions.
"Our aim is to improve if it is possible our kind of play to have more continuity, to do better and stay involved in all the competitions until the end of the season, to give continuity to the victory of last season," Chelsea manager Carlo Ancelotti said. "We went out too early and want to do better this season."
Chelsea's powerful attack will be weakened by the absence of striker Didier Drogba, who was suspended for two games by UEFA after receiving a red card in a 1-0 loss to Inter Milan in the Champions League in March.
Chelsea captain John Terry, however, returned to the squad for Saturday's 3-1 win over West Ham after recovering from a hamstring injury and is available for Wednesday's game.
Midfielder Frank Lampard, who has been sidelined following hernia surgery during the recent international break, and defender Ashley Cole did not travel with the team to the northwestern Slovak city. Long-term injured defender Jose Bosingwa is also absent.
"Jose still needs some time," Ancelotti said. "Frank also needs some more time before he is ready to play, but he should be okay for the game on Sunday."
Ancelotti said Cole was not injured but needed rest.
Zilina coach Pavel Hapal is hoping to cause an upset on the Slovak side's Champions League group stage debut.
"Chelsea is an extremely difficult opponent to beat, but we'll be playing and fighting for a victory," Hapal said. "In football, everything is possible ... Our players are looking forward to the match. It'll be a great experience for us."
Hapal has all its players available, including Gambian striker Momodou Ceesay, who proved lethal in the Champions League qualifying with two goals in the playoff that helped Zilina knock out Czech champion Sparta Prague 3-0 on aggregate.
The 21-year-old Ceesay hoped to join Chelsea two years ago but ended up at Belgian club KVC Westerlo before joining Zilina this year.
"You can't expect us to focus just on defense," said Hapal, a former Czech Republic international who played in the Champions League for Sparta Prague. "That would be a silly thing to do."
"We have to be brave to succeed against Chelsea. We'll certainly try to score at least a goal and do all we can to get a good result."
Zilina started well in the defense of its domestic title and remains the only team without a loss in the Slovak league with four wins and four draws.
The two have met before when Chelsea eliminated Zilina in the third qualifying round of the Champions League in 2002, winning 2-0 at Zilina and 3-0 at Stamford Bridge, with Terry and Lampard both in action.
Marseille hosts Spartak Moscow in Group F's other game.