Chelsea defender Cesar Azpilicueta has warned his side to learn from the mistakes they made during their last title defence when the new campaign begins next month.
The Blues stormed to the 2014-15 Premier League title under Jose Mourinho, but by December of the following season Mourinho had been sacked having made the club's worst start to a campaign since 1979, leaving them just above the relegation zone.
Chelsea ended up finishing the season 10th in the table and, having bounced back with a record-breaking title success last term, Azpilicueta is keen to avoid another disastrous defence.
"After being champions three years ago we had a terrible season and we have to learn from this," he told reporters.
"We know after being champions of the Premier League, every team we are going to face, they want to win more than before so we know that it is going to be harder. That is what we are working on in pre-season, to get into the best shape as soon as possible and to fight for it because it is a big challenge.
"We are back in the Champions League, we are the current Premier League champions and we have a big season ahead of us."
Chelsea begin the new Premier League season at home to Burnley on August 12.