Jose Mourinho's men return to the continent's elite club competition against the team they defeated 5-2 on aggregate in the Europa League semifinals last season.Chelsea's bid to win a major European trophy for a third straight season begins when the Blues host Basel in the Champions League.
The Premier League side won the Europa League last season, while it lifted the Champions League in the 2011-12 campaign, and it will be determined to claim the main prize again with Jose Mourinho back at the helm.
Chelsea and Basel are well acquainted, having met in the semifinals of the Europa League last season, with the Blues winning 5-2 on aggregate. That success came under interim manager Rafael Benitez, though, with Mourinho in charge now as he looks to win the title for the third time.
The Portuguese manager has won the Champions League at both Porto and Inter but is yet to win it at Chelsea, coming closest in 2004-05 and 2006-07, when he guided the Blues to the semifinals.
The Londoners have not made an ideal start to the season, losing to Bayern Munich on penalties in the UEFA Super Cup in August while winning just two of their first four Premier League matches. As a result, they lie sixth in the Premier League table, with Saturday's 1-0 defeat at Everton fresh in the memory.
Cameroon international Samuel Eto'o made his debut in that fixture, but the 32-year-old striker was guilty of missing several chances. Mourinho will expect more from the former Inter player, and Spaniard Fernando Torres may start as a result of his substandard performance.
Chelsea's array of young stars could all play big roles in the Champions League this season, with Oscar, Eden Hazard and Andre Schurrle all impressing in the early stages of the campaign.
Basel has its own stars to boast, and among those is veteran forward Marco Streller, who has already racked up four goals in just five games in the Swiss Super League, and Egyptian forward Mohamed Salah, who leads African World Cup qualifying with six goals.
The club's league form has been good, losing just one of its seven matches this season, and it sits third in the table as a result.
The Swiss side has played giant-killer before. It essentially knocked Manchester United out of the group stage in the 2011-12 Champions League by beating the Red Devils on the last matchday, and Murat Yakin's side had to work hard for its spot in this year's competition. It beat Maccabi Tel Aviv 4-3 on aggregate before toppling Ludogorets 6-2 in the playoff round.