Chelsea boss Jose Mourinho said his side had been given a tough draw in the Champions League group stage.
Chelsea will play Liverpool, Real Betis of Spain and Anderlecht from Belgium.
"This group is dangerous because in the third and fourth seeds there were some smaller teams, but we got Anderlecht and Betis," he said.
"Anderlecht have a big history in Europe with much experience of the Champions League. It is the debut for Betis but they are very strong."
Chelsea chief executive Peter Kenyon said he was looking forward to taking on Liverpool, the side which knocked the Blues out at the semi-final stage last season.
"We always have great games against Liverpool and after last season's semi-finals I think everyone thought it was fated we would meet again given Liverpool's special situation," he said.
"We have the utmost respect for them as a club and, of course, as defending European champions they will want to defend that title as best they can."