London - Jose Mourinho insists his Chelsea side must do "everything" they can to qualify for the next stage of the Champions League and avoid the chance of dropping down into the Europa League.
Speaking ahead of Chelsea's opening Group G match against Schalke 04 at Stamford Bridge on Wednesday, the Chelsea manager said it would be detrimental to his players' development should the team have to compete in the second-tier competition.
Teams finishing third in the Champions League group stage go into the Europa League, joining the competition in the knockout phase.
Mourinho is bidding to become the first manager to win the Champions League with three different clubs but he is only concentrating on the six group games to ensure his team finish in the top two and progress to the round of 16.
"The competition is part of my history and I'm part of the tournament's history. To win with three clubs would be unique," Mourinho, who won the competition when in charge at Porto and Inter Milan, told a news conference on Tuesday.
"Do I want to try to win again? Of course I want to. I have many years ahead of me. But in this moment I only think: don't play Europa League.
"It would be very bad for the evolution of our players to go to Europa League. We have to qualify. We have to do everything to qualify."
Chelsea have started the season in emphatic fashion, winning their opening four league games with a mixture of power and panache.
In stark contrast Schalke have endured a winless start in the Bundesliga, languishing near the foot of the table having taken just one point from their first three matches.
Mourinho, however, said league form will not matter and Chelsea will be wary of their opponents despite beating them 3-0 home and away at the same stage of the competition last season.
"They drew against Bayern Munich, obviously they lost their last match 4-1 but I don't see that as a drama or having a consequence in the Champions League," Mourinho said.
"I don't see a relation between the fact they lost the last match. Probably it will make them stronger. Probably they can discuss the mistakes they made, they can try to have a different approach to be a better team and a difficult opponent.
"In this moment it is a short competition of four teams for us, six matches. Everything is different," he said of the group which also contains Slovenian champions NK Maribor and Portuguese club Sporting Lisbon.
Mourinho will have a full-strength squad to pick from because striker Didier Drogba has recovered from the ankle injury which forced him to miss Saturday's 4-2 win over Swansea City in the Premier League.