Chelsea manager Roberto Di Matteo has warned his side against complacency when they face Benfica in a Champions League quarter-final second leg at Stamford Bridge here on Wednesday.
Chelsea are 1-0 up following their victory in Portugal last week and will be strongly fancied to reach their sixth semi-final in nine years.
But Di Matteo has urged his team not to get ahead of themselves as they contemplate a possible semi-final with either reigning champions Barcelona or AC Milan.
"It is a danger," said the Italian. "This is half-time and we're leading 1-0. But a 1-0 lead is basically nothing.
"Our players are aware of this, and we'll have to go into this game with the right attitude.
"Nothing has been done yet. We're aware of that. We need to go and qualify for the next round."
Di Matteo added: "This tie is far from over. They (Benfica) have scored in every away game of their Champions League season, so it's a difficult task tomorrow night."
Benfica boss Jorge Jesus insisted Chelsea were "lucky" to be ahead in the tie, saying: "Chelsea obviously have the upper hand, but we are going to approach this game in the same manner as we would have if we had won the first game.
"Chelsea had quite a lot of luck in the first match, considering we dominated the match.
"We have the quality to win this game, obviously, and I'm sure that -- this time round -- we can turn the tables on Chelsea and do the same as they did in Lisbon."
Jesus added: "They (Chelsea) came out to play for a 0-0 draw and ended up getting a win."
Chelsea are in the midst of a tough schedule of matches, and should they reach the semi-finals will end up playing 11 times in just 40 days.
They had been hoping to persuade the Football Association to bring forward the kick-off time of their FA Cup semi-final against London rivals Tottenham at Wembley on April 15 from 6pm local time (1700GMT) in a bid to give them more time to prepare for a possible Champions League semi-final.
But the FA are unlikely to change the kick-off time and Di Matteo, brought in as interim boss after Andre Villas-Boas was sacked, tried to put a positive slant on Chelsea's packed programme.
"I think there are a lot of clubs that would like to have so many games, to be involved in all these competitions.
"It's very demanding for the players, but we're in a good place. All the players are available, so that will help us."
He added: "It might become an issue at some point. I don't know.
"Fortunately, we have a fully fit squad, which will help us in the run-in, to be able to play every player we have and give everybody a chance."
Didier Drogba (foot), David Luiz (ankle), and Raul Meireles (knee) all trained Tuesday and are expected to be available for Wednesday's match.