Before the last strands of blue ticker tape were being swept from the Stamford Bridge pitch on Sunday, Chelsea manager Jose Mourinho would have cast his mind forward to the task of retaining the Premier League title. Even the club's most blinkered critics could not argue that Chelsea were unworthy champions. The 1-0 win over Crystal Palace secured the coach's third league title for Chelsea, following the back-to-back triumphs he masterminded during his first spell in charge of the Blues, when his tactical nous and owner Roman Abramovich's money proved an irresistible mix.In the days leading up to Chelsea's coronation, Mourinho claimed any celebrations would be as "quick as a flash" and "five minutes later I move on. I have to think about next season."The serial trophy-gatherer continued the theme once the job was done, alluding to the fact that next season will be an even bigger challenge for his squad."This group has now started by winning the League Cup and the league, but we know it is very difficult and every other team will become even stronger," the Portuguese warned."This is not the best country to be a force to dominate football, but obviously we are going to try to be there at the top of the league and try to win again."Leading striker Diego Costa is 26, goalkeeper Thibaut Courtois is 22, midfielder Cesc Fabregas is 28, holding midfielder Nemanja Matic is 26 and veteran John Terry's defensive partner, Gary Cahill, is 29 and still improving.With the energetic Willian still only 26 and the dazzling Eden Hazard a relative pup at 24, Chelsea's framework looks guaranteed for several seasons.But Mourinho, like former Manchester United manager Sir Alex Ferguson, knows that standing still is fatal.That is why a couple of marquee signings will surely be heading for Stamford Bridge to bolster Mourinho's ambition of taking Chelsea to the next level and challenging the likes of Barcelona, Real Madrid and Bayern Munich in next season's Champions League. ..